QMy story is set in Toronto in 1906. How would a semen stain on a petticoat be identified? How long after its deposition would such an identification be possible? If this was an attempted rape, what other legal issues should I consider?
Whitney Smith
Author of Lucy Speaks
London, England
AThe first test for semen was the microscopic detection of sperm. This was established in 1839 by H.L. Bayard and was improved by W.F. Whitney when in 1897 he discovered a stain that is currently called the Christmas Tree Stain. This chemical fixed and exposed semen for easy viewing under a microscope. The first chemical test would come in 1896 with the discovery that teriodide of potassium caused a reaction with semen, but the first reliable chemical test for semen was the acid phosphatase test discovered in 1945.
This means that your sleuth has a couple of options. If the stain is fresh, maybe twelve to twenty-four hours, he might examine the material under a microscope and see intact and even motile sperm. If it is several days old, he might stain it with the Christmas Tree Stain and see dead sperm or sperm heads, remnants of the sperm. If he was aware of the teriodide of potassium test, he might also employ that.
Each of these would allow him to say that semen was indeed present. Then it would be up to the judge and jury to decide if there was an innocent reason for the suspect’s sperm to be on the young lady’s clothing or if a rape occurred. Rape is a legal term, not a medical one. These tests only prove that semen is present but not how or why it was placed where found.