‘How have these hands been preserved?’ asked Ridpath frowning.
‘Probably by placing them in a sealed jar with the embalming fluid. Think of a museum or a lab keeping a specimen.’
For a second, Ridpath remembered what Turnbull has said about medical students. Was this a university prank by somebody with a perverse sense of humour? ‘Somebody placed these hands in jars?’
‘That’s what I said, Ridpath. It means they have been preserved as they were when they were severed from the arm. I’ve sent some samples to the lab for testing. We should know the composition of the embalming liquid soon.’
‘How does that help?’ asked Ridpath.
‘Each company produces embalming fluids with different levels of formaldehyde, glutaraldehyde, phenol and methanol,’ Dr O’Casey interrupted. It was almost as if the two pathologists were competing with each other to provide information.
‘Interestingly, the EU voted to restrict the use of formaldehyde by funeral directors for embalming in 2018, but there was a delay in the introduction of the legislation to allow them to find alternatives until 2023. As we have now left the EU, nobody has a clue whether this legislation will ever be introduced.’
‘Why was it banned?’
‘Strictly speaking, it wasn’t banned,’ said Schofield, ‘its use was restricted because studies had shown prolonged exposure was linked to nasopharyngeal cancer.’
‘It causes cancer and you asked me to smell it,’ said Oliver Davis.
‘A single exposure is not likely to cause any harm, Detective.’
‘Unlikely?’
Ridpath brought them back on track. ‘If we know the composition, we can find out where the embalming fluid came from?’
‘Correct, Ridpath. There are also different levels of saturation of the embalming liquid in each hand. The two male ones seem to have far less than the female hand.’
‘Does that suggest the person who severed the hands was an undertaker, mortuary attendant or maybe a scientist?’
‘Not necessarily. These days many people have access to embalming fluid, all the components can be bought on the internet.’
‘My dad buys embalming fluid,’ said Davis.
All the other people in the morgue stared at him.
‘What? He stuffs animals. It’s his hobby.’
‘I would keep that quiet in the station, if I were you, DC Davis. Anything else, Doctor?’
‘A couple of things. Because of the use of embalming fluid, I have no way of knowing when these hands were severed.’ Dr O’Casey spoke again.
‘So they could be two, twenty, or two hundred years old?’
‘Probably not the latter,’ said O’Casey.
‘Why?’
She tapped the computer keyboard again, bringing up the X-ray of the male hand. ‘See the white circles on the proximal phalange on the index finger.’
‘Sorry, where?’
She held up her own hand to show him. The fingers, despite being sheathed in a glove, were long and surprisingly elegant. ‘Here. They indicate a plate was placed to help support what must have been a bad fracture. The plate was later removed, however. Looking at the hand, the scar is small, with flap surgery by a plastic surgeon used to give the hand a near normal appearance, indicating for me that the surgery was performed in the last twenty years or so, certainly no later.’
‘From roughly the year 2000 onwards?’
‘Correct. I don’t think it would have been done earlier. Probably in the last ten years or so.’
‘So our older man had surgery recently. Interesting. What about DNA and fingerprints?’
‘Until a few years ago, it was difficult to extract DNA from embalmed specimens. Its recovery is often severely compromised by the presence of formalin. But can you imagine the research possibilities if scientists could extract DNA from mummies or from embalmed specimens held in old laboratories?’
‘They could investigate ancient diseases and evaluate how DNA has changed or been modified.’
The doctor stared at him. ‘You surprise me, Ridpath.’
‘My daughter has been doing DNA in biology. I have to keep up.’
‘Congratulations to your daughter. Anyway, new techniques have been developed using a three-step enzymatic digestion protocol. This procedure can then be integrated into traditional phenol and chloroform extraction, a modified manual DNA IQ or automated DNA IQ/Te-Shake-based extraction in order to recover DNA for downstream applications.’
‘What? Could you repeat that?’ asked Davis.
‘It means we can get the DNA,’ answered Ridpath.
‘Maybe.’
‘There’s a “but”, is there?’
‘In science, there’s always a “but”, DI Ridpath.’ A slight pause. ‘But brain, heart or liver tissue have generally been used. We can obtain DNA from bones or bone marrow, but I don’t know if the embalming process has deteriorated the quality of these bones.’
‘How will you know?’
‘By trying to extract DNA. I’ve already rung the lab and warned them of the issue. At the moment, they are frantically ringing up their pals at the University of Manchester to check the process. A couple of years ago they extracted DNA from two mummies that were thought to be brothers. They found they had the same mother but different fathers.’
‘So it is possible?’
‘It might be possible.’
‘And what about fingerprints?’
‘We’ve already taken them…’
‘There’s another “but”, isn’t there?’
‘Fingerprints decay on corpses; skin slips and shrinks. And what most people don’t know is fingerprints themselves change slightly as people age. In this case, we would normally use thanatopractical fingerprinting.’
‘What?’
‘Fluid is extracted from other parts of a body’s remains and used to restore tenseness and volume to the fingers in order to plump them for printing.’
‘But we don’t have other parts of the body.’
‘Precisely. We hope the embalming process has prevented the decay so we can get prints, or we could use silicone putty to obtain a casting capturing the detail of the ridges.’
‘Again, we won’t know until the lab reports back?’
‘Right. One final matter. We have taken scrapings from beneath the fingernails on all three hands. We’ve sent them to the lab, but again…’
‘Not my favourite word, “but”…’ said Ridpath.
Dr O’Casey ignored him. ‘But, again, if the hands have been in embalming fluid, any material we discover may have been compromised.’
Dr Schofield checked his watch. ‘There’s nothing else from us, Ridpath. From now on, it’s a waiting game, until we get the tests back. We’ll send our topline report tomorrow, following up with the lab reports as and when they come in.’
‘Can you ring me as soon as you find out anything?’
‘No problem.’
‘One last question. Do we know how these people died?’
‘Without the bodies, it’s difficult to tell. Toxicology might help, but I doubt it. There’s only so much science can do, Ridpath. I’m afraid the rest is up to you now.’
‘Isn’t it always?’
Dr Schofield stopped for a moment. ‘One more thought has occurred to me.’
‘What’s that?’
‘If the hands were all severed using the same type of hacksaw, it suggests—’
‘The same killer in each case,’ interrupted Ridpath. ‘Doctor, I think we are thinking along the same lines. Are we looking for a serial killer?’