Familial testing, which uses biological relatedness as the trigger for criminal investigation, ensures that groups with more children and large families relative to other groups will be at higher risk for genetic surveillance.
In March 2003 motorist Michael Little suffered fatal injuries when a drunken individual hurled a brick from a footbridge in Surrey County in the southeast of England. The brick pierced the windshield of his moving vehicle, hit him in the chest, and caused him to suffer a fatal heart attack. Blood traces left on the brick were believed to be those of the perpetrator. The blood, it turned out, was from a wound the perpetrator had received during an earlier attempt to steal a car. Police profiled the DNA in the blood and compared it with 2.35 million profiles it had stored on the national U.K. database at that time. There was no match. They also conducted a DNA dragnet in the area, collecting DNA samples from more than 350 young men. Six months after the crime had been committed and still with no leads, the police decided to go back to the database, but this time to run a search not for a perfect match, but for one where 11 or more of the 20 alleles used in the British system matched. The search turned up 3,525 potential siblings to the source DNA.2 The police narrowed this list to 25 white males who lived in the geographical region of the crime. One of these matched at 16 out of 20 alleles. This near match led the police to Craig Harman, a brother of the source profile and a prime suspect who admitted to and was convicted of the crime.3 Harman was the first person in the world to be convicted following identification through a familial search of a DNA database.4
“Familial searching” of databases represents a new method of creating suspects in the absence of an immediate cold hit. These searches are premised on the notion that siblings and other closely related individuals share more common genetic material than unrelated individuals. Therefore, a DNA profile that is a near match to the DNA found at a crime scene may be that of a first-degree relative of the actual perpetrator (i.e., a parent, an offspring, or a full sibling). The source of the near match, then, may lead the police to the criminal suspect and, in some cases, provide valuable information about that individual.5
The most common method of familial searching involves generating a list of possible relatives of the unknown person (whose DNA was picked up at a crime scene) by performing a profile search of a forensic DNA database that is designed to find “partial matches” between crime-scene evidence and offender profiles. In the Combined DNA Index System (CODIS) the term “search stringencies” describes one of three search modalities. A “high-stringency” search means that all alleles of the loci that are present in both DNA profiles (crime-scene DNA and database profiles) are identical. This represents the standard search for a cold hit, where the crime-scene profile matches exactly one and only one profile on the database. In a “moderate-stringency” search the alleles of a locus (among two DNA profiles) with the least number of distinct alleles must be present in the corresponding locus of the other DNA profile. For example, under “moderate stringency” one DNA profile with STR alleles 7, 10 will generate a match with another profile with STR alleles 7, 7. The heterozygote 7, 10 is deemed a “moderate-stringency” match with the homozygote 7, 7.
For a “low-stringency” match (used to find parent-child relationships), each locus that is compared between two DNA profiles must have at least one allele of that locus present in the other DNA profile. Thus a locus with STR 7, 10 would meet the standard of a “low-stringency” match with locus STR 3, 7.6
In a second familial search method police may conduct what is called a “rare-allele” search, in which they analyze the crime-scene DNA for highly unusual DNA signatures. Close relatives of those matches are then tracked down and asked to “voluntarily” provide a DNA sample.7 A third method of DNA profile searching is a variant of the second. It considers both the number of matching alleles resulting from a low-stringency search and their frequencies in a population. It is designed to reduce the number of false positives, that is, identification of individuals who are not relatives of the perpetrator.
Although this relatively new use of forensic DNA databases has led to a handful of somewhat remarkable success stories, familial searching, when practiced routinely, effectively expands DNA databases to all the close blood relatives of the individuals in the database, subjecting entire families (and perhaps even neighborhoods or even ethnic populations) to lifelong genetic surveillance. This gives rise to a number of social and ethical questions that deserve serious consideration.
Techniques and Practices
The premises behind familial searching are twofold. First, close matches in DNA profiles are more likely to indicate that the sources of the DNA are close family members rather than two unrelated individuals. Second, the closer the DNA match is, the higher the likelihood that the individuals are related, particularly when the matching alleles are rare in the general population. The most common and simplest technique used to identify potential relatives of suspects of a crime in the absence of a complete match with the database is allele counting, where forensic investigators compare the overall number of alleles shared between the crime-scene evidence and the database profiles. Generally speaking, the larger the number of shared alleles, the greater the probability of family ties. Siblings, on average, have about 18 of 26 possible alleles in common, while unrelated individuals average about 8 out of 26 in common.
BOX 4.1 Serial Killer Found from Sister’s DNA
In 2006, 49-year-old James Lloyd was convicted of four rapes and two attempted rapes that had occurred between 1983 and 1986. A father of two and described as “a wealthy businessman,” Lloyd was discovered to be the notorious “Dearne Valley Shoe Rapist,” who had tied his women victims up with tights and stolen their shoes. The police got to Lloyd through his sister, who was in the database for a drunken-driving conviction. Forensic scientists narrowed an initial partial-match list and provided the South Yorkshire Police the names of 43 people in the database who were possible relatives of the sex offender. In following up on the 43 names, police knocked on the door of Lloyd’s sister, who told the police that her brother roughly fit the age and height of the wanted individual and agreed to contact him. The sister called her brother and warned him that the police were after him. Upon hearing that he had become a suspect, Lloyd attempted suicide by trying to hang himself in his home but was saved by his 17-year-old son. While arresting him, police found more than 100 pairs of stiletto-heeled shoes hidden behind a secret trapdoor on the premises of Lloyd’s printing firm, where he worked. Lloyd pled guilty to four rapes and two attempted rapes and was sentenced to life imprisonment.
Sources: Tony Lake, chief constable, Lincolnshire Police, presentation before the FBI Symposium on Familial Searching and Genetic Privacy, Arlington, VA, March 17–18, 2008; Paul Sims, “20 Years After His Evil Reign, Shoe Rapist Is Unmasked by His Sister’s DNA,” Daily Mail (London), July 18, 2006; Andrew Norfolk, “Genetic Bar Code That Reopened the Case,” The Times (London), July 18, 2006.
Allele Counting: High, Moderate, and Low Stringency
As discussed in chapter 2, in the U.S. DNA data-banking system a complete match of two DNA samples occurs when all 26 alleles in the 13 loci (two alleles per locus) are identical, that is, each of the alleles at the locus has the same number of short tandem repeats (STRs). The FBI’s definition of a “partial match” requires that the crime-scene DNA and the offender DNA profiles share at least one allele at each genetic location tested, but the definition was not intended to address familial (or kinship) relations.8 In the hypothetical example in table 4.1, four samples, A, B, C, and D, are compared at locus number 1. The number of STRs for alleles at locus 1 is identical for samples A and B. If all 13 loci show the same concordance, we have an exact match for the samples.
In the event of a partial match, STR values will not be identical for all 26 alleles. Sample C matches the crime sample at moderate stringency, while sample D matches A at low stringency.
TABLE 4.1 High, Moderate, and Low Stringency for a Single Locus
The U.S. CODIS software system was designed to run moderate-stringency searches. This means that when a search is conducted against CODIS, the computer compares a given DNA profile with the database, looking not only for perfect matches but also cases where, for one or more loci, one sample contains only one allele (sample C, 9) and the other is heterozygote (sample A, 9, 13), with one of the alleles the same as the single one. This search criterion was designed not for purposes of conducting familial searches, but instead for capturing cases where DNA from a crime scene is partially degraded (so that the crime-scene DNA profile is a partial profile), or where the crime-scene sample may contain a mixture of two or more DNA profiles, or where “allelic dropout” (failure to detect an allele during sampling or failure to amplify an allele during the polymerase chain reaction) or a mistyping may have occurred. In other words, the intent of the moderate-stringency search was to build in a safety factor so that suspects who do have a profile that is identical to that of the crime stain but who would be overlooked by a high-stringency match search will in fact be identified. The CODIS software system was not set up to run low-stringency searches routinely, although it presumably would not be difficult to change the search parameters of the software.
For familial searches, forensic investigators must decide the criteria for a partial match. Some states use 13 alleles out of 26 to define a partial or low-stringency match. The state of Florida requires 21 out of 26. Investigators can examine the allelic similarities in partial matches and make predictions about how closely related the donors of the DNA samples are. They do this by making use of statistical information from large databases of the allelic homology of the DNA from family relations.
Henry Greely and colleagues reported on the allelic matching statistics for first-, second-, and third-degree relatives.9 A close or first-degree relative is a parent or sibling. On average they are expected to share about 50 percent of one another’s DNA variants (between 13 and 16 alleles). A father or mother and child match at no fewer than 13 alleles. Second-degree relatives include uncles, aunts, nephews, nieces, grandparents, grandchildren, and half brothers and sisters. These relatives share about one-quarter of their DNA variations. Finally, third-degree relatives, who consist of great-grandparents and great-grandchildren, share about one-eighth of their DNA variations (see table 4.2).
Greely and colleagues have estimated the probability of unrelated people matching a certain number of alleles on the basis of different scenarios. These calculations are useful benchmarks for understanding what the chances are that a low-stringency match will yield a relative of the perpetrator of a crime in the offender’s database. They conclude:
On average, the chance that an unrelated person’s genotype will match the genotype from crime scene DNA of 13 or more of the 26 alleles, allowing for all possible ways of distributing the matches across the markers, is around three percent. However, the chance that two unrelated people match at thirteen or more sites with every marker having at least one match (as will occur for parent-child pairs) is about one in two thousand.10
Matches from these criteria, then, are likely to produce close family members. However, they are also likely to miss most family members. In a memorandum sent to Attorney General Jerry Brown of California, Michael Chamberlain, head of the state’s DNA legal unit, wrote: “Under the FBI’s definition of partial match, it would preclude detection of 99.9% of brothers, many of whom have no alleles in common at a genetic location.”11
BOX 4.2 Familial Search Reveals a Posthumous Suspect
On September 16, 1973, two 16-year-old girls were raped and strangled in southern Wales, United Kingdom. Some months later a third 16-year-old girl met the same fate. The similarity of these heinous murders suggested that they could have been committed by the same man. During the initial investigation the police focused on interviewing 30,000 individuals. Subsequently, using techniques such as psychological profiling and an intelligence-led screen, police targeted 500 potential suspects, including a man named Joseph Kappen, but there was insufficient evidence to charge any of these individuals. In 2000, 27 years after the crimes were committed, investigators in the Forensic Science Service obtained DNA profiles from clothing stains of two of the girls and submitted the profiles to the United Kingdom’s National DNA Database (NDNAD). Although no exact match was found, a low-stringency analysis indicated that the DNA partially matched the DNA profile of a man named Paul Kappen. Police surmised that someone in Kappen’s family was the murderer, and this led them back to Paul Kappen’s father, Joseph, who had since died in 1990 at age 49. Meanwhile, in 2002 a comparison of the crime-scene DNA of the third girl’s murder showed that the three crimes were linked. British law-enforcement authorities obtained DNA samples from the Kappen family, including Paul Kappen’s mother and his siblings. The close matches between the crime-scene DNA and family DNA profiles were sufficiently credible for the police to obtain a warrant to exhume the body of Joseph Kappen. After his body was exhumed on May 17, 2002, it was learned that his DNA was an exact match with the crime-scene DNA from the three murders. Forensic investigators found the murderer by familial searching, albeit posthumously.
Source: Robin Williams and Paul Johnson, “Inclusiveness, Effectiveness and Intrusiveness: Issues in the Developing Uses of DNA Profiling in Support of Criminal Investigations,” Journal of Law, Medicine and Ethics 33, no. 3 (2005): 545–558.
Limitations of Allele Counting
Partial-match searches give rise to a number of questions that are technical on the surface but quickly become ethical. First, there is the question whether partial-match searches will miss potential relatives (false negatives). The second question is whether these searches will falsely identify unrelated individuals (false positives) and send investigators off on wild-goose chases. As was seen in the Craig Harman case, partial-match searches can yield results in the thousands. Ultimately, the question becomes, “How close is close enough?” In other words, what is the appropriate threshold for determining whether a partial match is likely to have revealed a relative of the actual perpetrator, warranting further investigation?
The false-negative and false-positive problems are compounded by the search criteria employed by the CODIS software system, which is not only used in the United States but also has been exported to at least one-fifth of the European countries using forensic DNA databases.12 Canada also employs CODIS software. The FBI gave the system to the Royal Canadian Mounted Police for free.13 As noted earlier, the system was designed to perform moderate-stringency searches for the 13 CODIS markers. The original purpose behind its use was to account for instances where crime-scene samples are compromised—for example, where they are partially degraded or in cases where there is a mixture, so that it is difficult to tell which alleles come from the alleged perpetrator. As applied to looking for family members, moderate- and low-stringency searches will pick up most parent-offspring relationships, since a child necessarily inherits one allele from each of his or her parents. However, as pointed out by researchers at the University of Washington, a moderate-stringency search will miss the overwhelming majority of full as well as half sibling relationships.14 This is because for each of the 13 pairs of alleles in a DNA profile, there is a 25 percent chance that siblings will not match at either allele. But if this occurs at any one of the 13 pairs of alleles, the familial relationship will be overlooked at the level of a moderate-stringency match. It turns out that the chance is only about 1 in 1,000 that a sibling will be identified at the level of a moderate-stringency search.15
The problem becomes more complicated, however, if we move to a low-stringency search. By relaxing the search criteria, we will increase the chances of picking up real siblings, or other related individuals, thereby improving the false-negative problem. However, we will greatly exacerbate the false-positive problem; the overwhelming number of individuals identified will not in fact be related at all. The reason this occurs is simply because there is a significant sharing of alleles within the general population. What we are looking for in a familial search is not this general sharing but, instead, sharing that results from two individuals with a recent common ancestor. The problem with allele counting, whether of low or moderate stringency, is that there is no way to distinguish whether these matching alleles are an indication of relatedness—echoes of common ancestry—or are simply coincidental.
In practice, both low- and moderate-stringency searches may very well send law enforcement off on wild-goose chases, especially in cases where they are conducted against large databases. As Greely and colleagues reported, although the chance that two unrelated people match at 13 or more sites with every marker having at least one matching allele is small (1 in 2,000), even this small percentage can yield a high number of false leads when one is dealing with a database of several million.16 More recently, George Carmody, a population biologist at Carleton University and a member of the New York State Forensic Science Commission’s DNA Subcommittee, estimated that a low-stringency search against the U.S. national database would generate on the order of 8,000 false partial matches for every real sibling match.17 This number of false leads will necessarily grow as databases continue to expand.
The number of false positives will depend in part on the relative rarity of the alleles in the crime-scene sample. As Greely and colleagues have cautioned, “The partial match is only a lead—a relatively weak one for a common genotype though possibly a very strong one for a rare genotype.”18
Similarly, David Paoletti and colleagues have pointed out that the value of a given partial match is dependent on a number of important parameters, including the relative frequencies of the matching alleles, the number of initial suspects considered, and the population size, or the number of potential alternative suspects. They conclude that it is not possible to come up with a single threshold (such as “number of shared alleles”) for use in determining when a partial match warrants further investigation. A partial match of as few as 5 alleles out of 26 might be significant and sufficient grounds for follow-up investigation when all 5 of those alleles are rare and the alternative suspect pool is small. But when all the matching alleles are relatively common, as many as 15 alleles might need to be shared.19
Mathematical models (discussed in the next section) that predict kinship relationships from DNA can support a hypothesis that two people are related on the basis of a few shared alleles even when they are not related. In other words, aggressive police work can pursue family members of partially matched individuals on the basis of tenuous or tentative mathematical assumptions. In one study of 194 Caucasians profiled by the FBI on 13 loci, pairwise comparisons of the profiles were made. In this sample 1,654 pairs of individuals partially matched at 9 loci, and 797 pairs partially matched at over 9 loci.20 Unless the mathematical models are validated and become canonical, their use in forensics will remain controversial.
BOX 4.3 The Case of the Grim Sleeper
A serial killer, colloquially named the Grim Sleeper, who had murdered African American women in South Los Angeles since 1985, left his saliva and other DNA at several killing sites. Los Angeles police connected the perpetrator to 10 victims. A genetic sample preserved from one of the crime scenes matched samples collected from a 14-year-old killed in 2002, the body of a woman killed in 2003, and another victim found in 2007. The Los Angeles police ran the DNA found at the crime scene against millions of genetic profiles of convicted criminals in the state DNA database. Police tried to locate the unknown killer’s relatives in the hope that there would be similar DNA patterns by comparing the crime-scene DNA profile (under low-stringency conditions) with those in the state’s DNA database of more than 1 million felons. Initially no suspects were found. Eventually the state forensic lab found a partial match in the Grim Sleeper case with Christopher Franklin, recently convicted of a felony, that suggested a father-son relationship. The trial led to Christopher’s father, Lonnie D. Franklin Jr., 57, when police found a DNA match from his saliva on a discarded pizza slice. In July 2010 Lonnie Franklin was declared the Grim Sleeper by Los Angeles police and charged with 10 counts of murder and one count of attempted murder.
Sources: Joel Rubin and Maura Dolan, “DNA Search Fails to Find Relatives of Unknown Serial Killer,” Los Angeles Times, December 3, 2008; Maura Dolan, Joel Rubin, and Mitchell Landsberg, “DNA Leads to Arrest in Grim Sleeper Killings,” Los Angeles Times, July 8, 2010.
More Advanced Familial Searching Techniques
Population geneticists and biostatisticians have recommended using more advanced statistical techniques for conducting familial searches as a way of improving both efficiency and accuracy. The most commonly agreed-upon approach is to use “likelihood ratios” (LRs). As applied to familial searching, this is a statistical method that goes beyond simple allele counting and instead evaluates the genetic evidence to support the likelihood that two individuals are related compared with the likelihood that they are not. In general, the LR is the ratio of two probabilities of the same event under different hypotheses. For DNA testing the LR is the probability of the observed genetic profiles given proposed familial relationships versus the probability of observing the genetic profiles if the donor of the evidence and the identified partially matching profile sources are unrelated.21 Charles Brenner, a consultant on paternity testing and forensic DNA practices, has described an LR as follows: “[It is the] amount of coincidence that you have to swallow if you want to believe that two profiles are similar merely by chance.”22
The benefit of using LRs is that they make better use of genetic information and produce a prioritized list of partial matches. In addition to comparing the amount of sharing between any two individuals with the amount of sharing that would be expected if those individuals were siblings or parent and offspring, the LR can take into account the relative frequencies of the matching alleles in the population. The rarer the alleles that match, the more likely it is that the match indicates a potential familial relationship.
Frederick Bieber and colleagues performed some mathematical simulations to investigate the chances of finding a true relative using this approach. Specifically, they ran a series of simulations by comparing an “unknown” sample with each registered offender in the database to determine the likelihood ratios of successfully identifying biological relatives of the offenders. Assuming a database size of 50,000, they argue that a parent of a child of a known offender would be identified 62 percent of the time as the very first lead (highest likelihood ratio) and 99 percent of the time among the first 100 leads (99 families would be investigated to find the one family related to the perpetrator). This assumes that the relative is in the database in the first place, and that the crime is committed in the state where that relative resides.23 They conclude: “Our simulations demonstrate that kinship analysis would be valuable now for detecting potential suspects who are the parents, children, or siblings of those whose profiles are in forensic databases.”24 LRs can also weigh the significance of a partial match on the basis of the racial and ethnic populations from which the DNA samples were drawn. For example, in the Caucasian population fathers and sons share an average of 16 out of the 26 CODIS-designated alleles, while two completely unrelated Caucasian individuals will share an average of 9 alleles. These figures will vary slightly across racial and ethnic populations. In groups that are more isolated and where there has been more inbreeding (e.g., cousins having children with one another), the number of shared alleles will be greater, even for so-called unrelated individuals. On the other hand, populations where there has been a lot of breeding across races and cultures and that have exhibited more mobility will show more allelic diversity and thus less allele sharing.
Although Bieber and colleagues are optimistic about the value of conducting familial searches using current techniques, others have pointed out that even these more refined techniques will produce a high number of false positives, especially when used in the context of large databases. High numbers of false leads result in resource-intensive investigations. In addition, these techniques are not likely to turn up any significant investigatory leads beyond full siblings and parental relationships.25
One way to narrow potentially long lists of possible relatives of suspects is to subject the stored DNA samples identified in a partial match to additional genetic testing. Kristen Lewis and colleagues advocate the use of ancestrytesting techniques—specifically Y-chromosome analysis and mitochondrial DNA sequencing—to exclude individuals from investigation who cannot be related to the true perpetrator through either paternal or maternal lineage.26 Y-chromosome (Y-STR) analysis involves examining genetic markers along the Y chromosome; since the Y chromosome is paternally inherited, it can be used to trace family relationships among males. Similarly, mitochondrial DNA (mtDNA) is inherited from the mother and can be used to trace back maternal lineages. Frederick Bieber and David Lazer suggest that Y-STR analysis alone could eliminate 99 percent of false leads.27 Others have recommended expanding the scope of genetic markers used in the DNA profile as a way of narrowing long lists of potential relatives. All these techniques would require accessing the stored biological samples of individuals in the database and subjecting them to additional genetic tests.
U.S. Policy on Familial Searches
In the United States the practice of familial searching was limited by a policy adopted by the FBI that prohibited the release of any identifying information about an offender in one state’s database to officials in another state unless the offender’s DNA was an exact match with the DNA evidence found at the scene of the crime (with limited exceptions for cases where slight differences between the profiles could be explained by degradation). In the summer of 2006 the FBI changed its policy in response to a request from Denver authorities after a close match was found between evidence taken from the scene of a rape and a convicted felon in Oregon, indicating that he was a potential relative of the actual perpetrator.28 The interim policy, which became effective on July 14, 2006, allows states to share information related to “partial matches” upon FBI approval.29 Following FBI authorization, discretion whether to release the offender information is left to the state that holds the information. According to the FBI memorandum distributed on July 20, 2006, “For situations in which there is no other available investigative information, the FBI Laboratory has instituted an Interim Plan that may permit the release of the offender’s identifying information.”30
The FBI’s interim plan defines a “partial match” as “a moderate stringency candidate match between two single-source profiles having at each locus at least one allele in common.”31 This plan did not allow information to be released between states as a result of low-stringency searches. In this way the FBI was insisting that the search parameters initially established for CODIS remain intact. Furthermore, the FBI distinguishes these partial matches from familial searching, claiming that these partial matches are “inadvertent,” as opposed to purposeful searches for incomplete matches. According to Tom Callaghan, FBI CODIS unit director, “The FBI does not do familial searching.”32
The FBI’s distinction between an “inadvertent partial match” and familial searching seems tenuous; after all, the follow-up to such a partial match is to seek out family members of that individual. Nonetheless, the FBI’s insistence that partial-match follow-ups do not constitute familial searching may indicate the agency’s own recognition that full-scale trawling of the databases is not authorized under current law and that allowing this more aggressive searching would render the database operations vulnerable to legal challenge. Whether legislative authority would be needed to authorize familial searching was a central question posed by the FBI itself at its national symposium on familial searching in March 2008.33
To be fair, the DNA Identification Act of 1994 that established CODIS is silent on the issue of familial searching and partial matches and simply states that the database will be used “for law enforcement purposes.”34 Nonetheless, there is some indication in the legislative history that Congress certainly did not intend for the database to be used to trawl for individuals other than those in the database. For example, Senator Herb Kohl from Wisconsin stated on the Senate floor in support of the DNA Analysis and Backlog Elimination Act of 2000:
Currently, all 50 states require DNA samples to be obtained from certain convicted offenders, and these samples increasingly can be shared through a national DNA database established by Federal law. This national database . . . enables law enforcement officials to link DNA evidence found at a crime scene with any suspect whose DNA is already on file. By identifying repeat offenders, this system does make a difference.35
In other words, the idea was to create a database of known, convicted offenders so that law-enforcement officials could link those offenders to other crimes they might have committed and to have a way of catching them if they acted again. It was not to use the database as an intelligence or surveillance tool to investigate other people who were not in the database.
Perhaps the more significant evidence that familial searching crosses a well-established line is in the design of CODIS itself. Familial searching of the database is not a new concept; it was well known during the time at which CODIS was established that the database could be used in this fashion. In 1992, two years before the establishment of CODIS, the National Academy of Sciences issued a comprehensive report that made a series of recommendations for DNA data banking and testing. The report addressed head-on the issue of familial searching:
The ability of DNA to recognize relatedness poses a novel privacy issue for DNA databanks. . . . To put it succinctly, DNA databanks have the ability to point not just to individuals but to entire families—including relatives who have committed no crime. Clearly, this poses serious issues of privacy and fairness. . . . It is inappropriate, for reasons of privacy, to search databanks of DNA from convicted criminals in such a fashion. Such uses should be prevented both by limitations on the software for search and by statutory guarantees of privacy.36
In addition, the Privacy Act of 1974 requires that a formal rule making be issued for any new government database that defines clearly the categories of individuals who will be affected by the database.37 Such rules were issued by the U.S. Department of Justice for the National DNA Index System (NDIS) at its inception in 1998. Those rules established four categories of individuals covered by the system: convicted offenders; missing persons and their close biological relatives; victims; and DNA personnel. In addition, the rules included the following safeguard: “NDIS will disclose to a criminal justice agency the DNA records of another criminal justice agency only when there is a potential DNA match.”38 Given that family members represent an entirely separate category of individuals affected by the database system, and that partial matches result in disclosure of information between agencies when a DNA match is not complete, it seems that, at the very least, a formal rulemaking process is required under the Privacy Act in order for the database to be used to identify potential family members.
The agency’s hesitation to cross the line was at one time shared by most state database administrators. At the national symposium on familial searching in March 2008, sentiments were nearly unanimous among the 50 state CODIS administrators and their legal representatives that they did not currently have authority to move forward with familial searching.39
Even so, it is not clear that the line the FBI is attempting to draw between “partial matches” and “familial searching” will hold as a practical matter. A memorandum dated August 2, 2007, from Tom Callaghan stated that a “Next Generation CODIS” was under development that would provide a new search engine capable of performing “joint pedigree likelihood ratio” analyses.40 Although the stated intent of the upgrade is to conduct missing person searches, it is hard to imagine how the states or the FBI will be prevented from using this for familial searches in criminal investigations. In the meantime, the interim policy appears to have encouraged some familial searching advocates to push harder at the state level to initiate statewide familial searching programs. Several states, including Florida, South Carolina, North Carolina, Colorado, Missouri, Oregon, Arizona, and Massachusetts, have agreed to disclose partial matches to law-enforcement agencies in accordance with the FBI interim policy. These states have generally focused almost exclusively on the technicalities of familial searching and very little on the political, legal, or ethical ramifications of such searches. In contrast, Maryland statutorily banned the use of familial DNA searches.41
BOX 4.4 A 14-Year-Old Offender’s DNA Leads Police to a Murder Suspect
A 20-year-old woman named Lynette White was fatally stabbed in southern Wales in 1988. It was one of the most brutal murders in Welsh history. The case went cold for 12 years, but the police were not ready to give it up. In 2000 forensic investigators completed a new DNA sweep of the victim’s apartment, hoping to acquire new forensic evidence. The sweep turned up spots of blood on a baseboard that had been missed on the first search. They profiled the bloodstain DNA and compared it with profiles in their national database but did not find an exact match. However, an allele in the crime-scene DNA was found in only 1 to 2 percent of the profiles in the NDNAD. By using a low-stringency familial search combined with geographical constraints, police found approximately 70 potential relatives of the person who had left the crime-scene stain. Forensic investigators eventually found a person in the NDNAD who had a reasonably close DNA profile to the crime-scene DNA—a 14-year-old boy who was not alive when Lynette White was murdered. The boy’s DNA was in the database because he had previously gotten into trouble with the police. The police began looking into the boy’s family and focused attention on the boy’s paternal uncle, Jeffrey Gafoor. Gafoor’s DNA was an exact match with the bloodstain, and he eventually admitted to committing the crime.
California’s Reversal on Familial Searching
The shift in the FBI policy also sparked disputes between states. Denver’s district attorney, Mitchell Morrissey, applied the interim FBI policy in familial searches to a cold case involving a Denver rape. The crime-scene DNA did not yield an exact match in CODIS, but a moderate-stringency search found what Morrissey believed could be a close family member who had been convicted of a felony in California. He requested information about the felon from California attorney general Jerry Brown in July 2007. On August 3, 2007, Brown reportedly denied the request, citing the need to protect the privacy of California felons who are not exact matches in CODIS. Brown noted that reporting on DNA near matches was beyond the scope of court opinions that authorize DNA database searches and could prompt a lawsuit.42
Five months later Rockne Harmon, a former senior deputy district attorney from Alameda County, California, and a strong proponent of familial searching, announced at the New York State Forensic Science Commission meeting on familial searching that California was about to change its policy on the release of partial-match information and unveil a full-scale familial searching program. He repeated these comments two months later at the March 2008 FBI symposium, and when he was asked by a representative from the Louisiana state lab why he was moving forward without legislative guidance, given the potential privacy and state constitutional concerns, he simply responded, “We’re doing it without legislation.”43
On April 14, 2008, the American Civil Liberties Union of Northern California filed a Public Records Act (PRA) request with the California Department of Justice (DOJ), asking for all records relating to the department’s policy regarding familial searching, as well as any plans to change its policy. Ten days later (the deadline for the California DOJ to issue a response) the agency released publicly a new “DNA Partial Match Policy.” A complete turnaround from Jerry Brown’s initial response against releasing partial-match information, the policy not only allows the release of information in the event of partial matches, in concert with the FBI’s interim policy, but it goes much further in explicitly allowing low-stringency searches. Requests for these searches are to be considered on a case-by-case basis. The crime-scene profile must be single source (not a mixture), the search must produce a “manageable number of candidates,” and Y-STR analysis is required.44 A minimum of 15 shared alleles is required for partial-match follow-ups; no minimum threshold is given for low-stringency searches.
California is the first state to release an official policy directive on familial searching. Some states, such as Oregon, updated their CODIS operations manuals to incorporate the FBI’s interim policy on partial matches. Massachusetts and New York have regulations that explicitly address the issue of low-stringency searches, requiring that a minimum of four loci be provided for a forensic search against the DNA database. The intent of these regulations seems to be to address the issue of crime-scene sample degradation or limited sample availability rather than familial searches. However, Massachusetts provides that “the laboratory . . . may, at its discretion, request that a search be performed using fewer loci if there are scientific reasons which support using fewer than four loci in a particular case, including but not limited to the apparent presence of mixtures, sample degradation, limited sample availability, or the possible involvement of relatives.”45 Where other states have permitted familial searches, the threshold of similarity required for allowing follow-up is ambiguously defined and described in terms of such matches needing to “be very, very close” (Virginia) or is set at an arbitrary number of alleles (for example, 21 out of 26 in Florida).
In the absence of both clear legislative authority and an established methodology for familial searching, the move by some states to rush forward with low-stringency searches is at best premature, if not irresponsible. The failures and complications of such a headstrong approach may not rise to the level of public discourse; in general, it is only the sensationalized success stories of forensic DNA that we tend to hear about, not the dead-end investigations, the wasted resources, or even the errors.
Just as the United Kingdom has enacted the most aggressive policies on DNA expansion, it has also introduced a number of new, controversial investigational techniques using DNA, including familial searching (see boxes 4.1, 4.2, and 4.4). Familial searching is currently used routinely in the United Kingdom for high-profile investigations. As of January 2008, 148 cases in the United Kingdom had been submitted for analysis using familial searching techniques. Seventy-nine of those cases were active at that time, and 15 of them had been cleared (i.e., someone is arrested or charged) or resolved (no convictions) through familial searching. Of those 15, 9 had resulted in convictions, 4 in no conviction, and 2 were still going through the criminal justice system in 2009.46 On average, the cases investigated so far in the United Kingdom using familial searching techniques have generated 1,500 to 3,000 partial matches,47 which are then narrowed using geographical parameters and Y-STR sampling.
Proponents of familial searching in the United Kingdom boast a 90 percent success rate for those cases where it has been employed.48 In addition, they argue that it saves money: Richard Pinchin of the U.K. Forensic Science Service claims that between $.5 and $2 million are saved for each murder investigation where familial searching is employed, simply because of a reduction in investigation time.49 Pinchin also argues that law enforcement should feel obligated to use DNA in any way it can to solve a crime, given the time and resources it has spent collecting DNA from crime scenes and establishing and building the national DNA database.
Unlike the United States, the United Kingdom has developed some procedural guidelines for familial searching. According to Tony Lake, chief constable of Lincolnshire Police and the former chair of the National DNA Database Strategy Board, familial searching is considered only for serious crimes where there has been no match with the database. Familial searching can occur only with approval by the custodian of the National DNA Database (NDNAD) and is approved as “proportionate and ethical” only if it is restricted to the most serious cases and if intrusion into the privacy of individuals is minimized. For each case, a series of search parameters is established, such as level of genetic similarity, allele rarity, age, ethnic appearance, surname, and geographical area. The United Kingdom routinely uses a number of techniques to narrow long lists of partial matches, including Y-STR analysis, mitochondrial DNA analysis, and, finally, taking swabs from relatives. “Swabbing teams” are trained to find a person’s DNA in the event someone refuses to give a sample and to handle cases where a potential revelation occurs for a family member who, for example, finds out that he or she is adopted.
So although the United Kingdom has moved forward more quickly with familial searching than has the United States, some recognition, at least, has been given to public concerns about the way in which these searches are conducted and how they might be followed up. Even so, the U.K. practice is not without criticism. Hugh Whittall, director of the Nuffield Council on Bioethics, has commented that the U.K. system still lacks a clear and transparent framework for determining the circumstances under which and how familial searching should be used.50 According to Robin Williams and Paul Johnson,
Discussions between ACPO [the Association of Chief Police Officers], the Home Office, the Information Commissioner, and representatives from the Human Genetics Commission, have resulted in an agreement about the circumstances under which such [familial] searches will be carried out and their results integrated into existing investigative procedures. However, the agreement is operationally sensitive and has not been publicly disseminated.51
A public consultation initiated by the Nuffield Council indicates that the public remains seriously concerned about whether familial searching constitutes an unjustifiable intrusion into personal privacy. The Nuffield Council has recommended that detailed and independent research be conducted on the operational usefulness and practical consequences of familial searching before it is more widely deployed.52
Civil Liberties and Familial Searching
From a civil liberties perspective, familial searching is problematic at several levels. First, if it is practiced routinely, it effectively expands the database designed to identify known offenders to include millions of innocent people—those who happen to be relatives of convicted offenders. These individuals have never been suspected of any wrongdoing, yet they are being placed under lifelong genetic surveillance by way of their relation to individuals who are in the database.
George Washington University law professor Jeffrey Rosen has noted that familial searching is inconsistent with a basic pillar of American political thought: “The idea of holding people responsible for who they are rather than what they’ve done could challenge deep American principles of privacy and equality.”53 The United States has a troubling history of profiling individuals on the basis of their biology, and familial searching, in this sense, plays into this history. Rosen has also argued that familial searching is antithetical to our founding fathers’ rejection of the “corruption of blood,” which under the common law of England stripped the descendants of anyone convicted of a felony of their right to inherit the felon’s estate or title. Section 3 of Article III of the U.S. Constitution states, “The Congress shall have power to declare the punishment of treason, but no attainder of treason shall work corruption of blood, or forfeiture except during the life of the person attainted.”54
In his carefully crafted memorandum on familial searching to California attorney general Jerry Brown, Deputy Attorney General Michael Chamberlain identifies four possible consequences for individuals who are in the database and are identified as part of a familial search: (1) they may be contacted by detectives; (2) they may not even have relatives who could have committed the crime; (3) they may have relatives who are completely innocent; and (4) they may have relatives who are not themselves in the database, but who will be under suspicion nonetheless. He sums up: “The Databank Program, designed as an investigative scalpel, could be used instead as an indiscriminate investigative fishing net.”55
This fundamental shift in the intent and purpose of the database—from one of investigation of known offenders to its use as an intelligence tool to investigate individuals outside the database without probable cause—may conflict with some state constitutional laws. For example, the right of privacy guaranteed by the California Constitution has been interpreted by the California Supreme Court to prevent the government (and business interests) “from misusing information gathered for one purpose in order to serve another purpose.”56
The use of the database to target innocent people also appears to be inconsistent with the very protections that have been built into most, if not all, state database statutes. First, although some states have moved to include categories of innocent people—for example, arrestees—in their databases, most states have in fact rejected these proposals on privacy grounds. In addition, states are required as a condition of participating in CODIS to allow for expungement of DNA records in situations where a conviction is overturned or a case is dismissed, although this usually requires that the falsely convicted individual initiate the process. It seems puzzling to say, on the one hand, that innocent people have the right to have their DNA removed from the system, but, on the other hand, that it is okay to mine the DNA of other innocent people by way of their relatives.
What balances are there (or should there be) against the unfettered use of familial searching? Let us suppose that a familial search brings police to the family members of someone in the national DNA data bank. The person in the data bank—the “genetic informant”—may not have committed any crime. Increasingly, U.S. states are including arrestees; England and Wales include all detained, charged, or arrested individuals over 10 years old. Now this individual is being questioned by police to divulge information about family members who are not yet suspected of any crime. Even if the individual is in prison and considered to have a lower expectation of privacy, he or she nonetheless has no obligation to report on personal matters of members of his or her family.
There are also privacy considerations of the relatives of the individual who is in the national database. Other than the fact that they are relatives of an individual whose DNA shares some limited homology with the crime-scene DNA, there is no suspicion against them for the crime in question. Their privacy must be intact until there is reasonable suspicion. Can investigators prompt them to give a DNA sample? Should investigators be permitted to obtain a DNA sample surreptitiously from family members?
Bieber and colleagues note that through familial searching “genetic surveillance would shift from the individual to the family.”57 Individualized suspicion expands to group suspicion. Courts have been resistant to give police warrants for suspicion based on group properties. The fact that a witness saw a man with a black hat commit a crime does not enable police to invade the privacy of all men with black hats. Courts will not issue warrants for such a group dragnet. It is also unlikely that courts will issue warrants for DNA searches of all family members of a low- or moderate-stringency match in a national database. But what if there were only a handful of individuals identified in a smaller database search? And what if only two of those had relatives who were of a plausible age range for the crime in question? And suppose that one of those relatives has a criminal record? Would that be enough suspicion to yield a warrant for that person’s DNA?
In a sense, familial searching creates a backdoor way for law enforcement to investigate people without their knowledge or consent, let alone a search warrant. The call to use Y-STR analysis and other techniques that require returning to the stored biological samples is especially troubling in this regard. These analyses can reveal sensitive information about individuals and their families—information that they themselves might not want to know. Such testing may run contrary to state genetic privacy laws. For example, Section 79-1 of the New York Civil Rights Law prohibits the performance of any genetic test (including DNA profile analysis) without the “written informed consent” of the individual and forbids any other unauthorized testing or dissemination or disclosure of test results.58
There are many other unanswered procedural questions associated with the follow-up by criminal justice to partial match searches. As discussed earlier, low-stringency searches can generate thousands of partial matches, and these will continue to grow as the databases grow. A partial match indicates only that there is some possibility that a relative of that person could have DNA that fully matches the crime-scene evidence; the probability that the partial match is useful depends, in part, both on the number of alleles that are found to match and on their relative rarity in the population. Even if the list can be winnowed by using a variety of the techniques discussed earlier, the police might be tempted to knock on the doors of tens if not hundreds of individuals, disrupting the private lives of many innocent people unnecessarily. These shotgun-style investigations result in personal and social harm in the form of distress and stigma. Another danger is that in following up with potential relatives or their family members, law enforcement may overstate the significance of the familial match and make it seem as though they “have the DNA.” This could lead some individuals to wrongfully confess to a crime they did not commit. In addition, if a partial match is not sufficient evidence to compel a relative to provide a DNA sample via a court order, what happens if those individuals refuse to provide a sample? What is the fate of the samples collected? Will they be destroyed if that person is excluded from the crime? Will there be a temptation on the part of law enforcement to follow people around to get their DNA surreptitiously when a court warrant cannot be obtained because there is insufficient evidence of probable cause?
Family searches may also reveal family secrets. Low-stringency database searches can bring nonsuspects into police inquiries that demand that they reveal intimate and personal information that falls well beyond establishing their identity. It is possible that some of this information could be sensitive and involve paternity, incest, immigration eligibility, human immunodeficiency virus (HIV) status, or fertility. Familial searches can also reveal unknown genetic relationships or an absence of a presumed genetic relationship. For example, a partially matching individual might name someone as a parent or child who turns out not to be genetically related to him or her, or a family member who does not know that he or she has a relative in prison could be contacted by the police and asked to provide a DNA sample. Sonia Suter, a professor at the George Washington School of Law, suggests that the risks to the family associated with these revealed secrets depend on why the information was hidden and how it is disclosed and to whom.59
Private information about the family, once it gets into police hands, can change family dynamics. A low-stringency search can create a large pool of suspects from the family. Erica Haimes puts an anthropological perspective on such searches:
Realizing that one is part of such a large pool of potential relatives could change an individual’s or family’s self-perception. Individuals might gain or lose social capital through that membership and the collectivity might experience an enhanced self-consciousness of themselves as a group. They might also, for the first time, define themselves as being “related” to each other.60
Frederick Bieber uses a license-plate analogy to explain why police seek to justify law enforcement’s investigation of partial matches. “Not investigating such leads would be like getting a partial license number in a getaway car and saying ‘well, you didn’t get the whole plate so we’re not going to investigate the crime.’” 61 But the license-plate analogy is problematic. When you buy a car, you agree to have a license plate and to make that license plate visible. The license plate protects you, as well as others. If your car is stolen, the license plate can be used to locate it. If you drive recklessly, someone can report you to the police. By all means, the requirement to have a license plate on your car interferes with your privacy, but this is a reasonable condition for owning a car that we all agree to and are all aware of. The same, it seems, cannot be said of our DNA. Following up a partial DNA match means potentially learning a lot of personal information about a person. It is not a requirement—at least not so far—that we turn over our DNA as a condition of living in this society.
Racial and Ethnic Disparities
Daniel Grimm questions familial searches on grounds of privacy and racial disparities. In regard to the latter, certain minority groups with larger-than-average families will be disproportionately affected by familial searches. More innocent people in large families will become suspects in familial searches. They will be subjected to harassment, surveillance, and DNA sample collection and possibly even permanent storage of the family’s DNA. On the basis of the demographics of Hispanic populations in the United States, Grimm concludes, “A partial match between a crime scene sample and an index sample from a Hispanic defendant will, on average, lead investigators to more biological relatives than if the sample had been from another group.”62 Grimm’s conclusions were already anticipated by Bieber and colleagues in a 2006 Science article. Although the authors argue that by using a combination of cold matches and familial searches, more crimes will be solved, they also conclude that familial searching potentially will exacerbate disparities among racial and ethnic groups that exist in the criminal justice system.63 In resonance with concerns about racial disparity associated with familial searching, Barry Scheck, cofounder of the Innocence Project, noted, “The genetic surveillance of innocents would be along racial lines. . . . I think it is a troublesome idea.”64
In practice, further honing in the lens of the criminal justice system on particular populations means that racial minorities who have committed no crime are far more likely to be targeted than white people. It also means that white criminals are more likely to get away with crimes than blacks or Hispanics. These gross imbalances, combined with the increasing use of familial searches, may have the deeper impact of reiterating the faulty and highly dangerous notion that criminal propensity is genetic and racialized.
We have seen how familial searching uses statistical methods to generate suspects in a crime where there is no prime suspect. Under this method forensic DNA has been transformed from a precise tool for identification into a blunt instrument for using DNA similarities to troll for family members of a person who happens to be in a DNA data bank—even while there are no independent grounds of suspicion of those family members. Anyone who has his or her DNA profiled in a state DNA data bank, whether or not that person has been convicted of a crime, brings his or her entire family unit under DNA surveillance. Although police, by tradition and law, have had the right to generate suspects to a crime, there has also been a legal tradition of protecting the privacy and rights of suspicionless individuals. The courts and state legislatures have yet to set boundaries or prohibitions on trolling data banks for suspects on the basis of the fact that the crime-scene DNA is statistically more likely than a random DNA profile to be from a member of the extended family of the so-called near match. Currently, familial searching is carried out without special protections for juveniles, people who voluntarily donate their DNA, surreptitious DNA profiling, and the threats that some families may face by becoming identified as “crime families” because they are more frequently brought up in so-called close matches.
