Murdered by a Murdered?

A grotesque and mystifying incident occurred on one eventful day in the year 1997. A woman was brutally murdered and the DNA sample of her suspected murderer was found on her nails. The baffling incident was that the DNA sample matched with the DNA of another woman who had been murdered three weeks before the actual murder.

The investigators were flabbergasted. Here was an ordinary and straightforward case. A murder has occurred, DNA sample of another person was found under the victim’s fingernails. Natural conclusion; the victim scratched the murderer in the tussle which led to her fatal end. Very straightforward. The DNA sample turns out to be the DNA of another woman who has been dead for weeks. The whole case comes crashing down!

The first thing that crossed Dr Mike Silverman’s (the national account manager for the Forensic Science Service at the time) mind was that as the victim’s body was taken to the same mortuary where the suspect’s body was kept, the autopsy reports may have been mistakenly interchanged. But the solution didn’t turn out to be so simple. As Dr Mike Silverman says “The victim had painted her nails with a distinctive leopard skin pattern and the cuttings that had been taken bore the exact same pattern. There was no doubt that they were the correct ones”.  Further Dr Silverman says “I then checked through the laboratory records to see if there was any way the samples could have been accidentally mixed-up".

This too turned out to be a non-starter as the two sets of samples had never been out of the lab's exhibit store at the same time. In any event, several weeks had passed between the analysis of the first and second clippings and different members of staff had been involved.”

Here was a perfect mystery thriller which would have had even Sherlock Holmes rubbing his hands and licking his lips in glee! The possibility of metaphysical activities and the fourth dimensions were widely debated. ‘Does the spirit or ghost of a dead person carry their DNA too?’ argued some paranormal experts.

It was then that Dr Silverman had a brainwave. What if the DNA sample was transformed from the scissors to the nails of the victim when the nails were cut for the autopsy? That idea not only led to the crux of this matter but also probably saved many innocent people from being pronounced guilty based on DNA evidence.

Dr Silverman says “It was while I was examining the mortuary records that I came across a possible answer. It transpired that the body of the first murder victim had been kept in the freezer for several weeks while the police carried out their initial investigation.
It had been removed from the freezer to allow the pathologist to take additional nail clippings the day before the body of the second murder victim had arrived at the mortuary.
The following day, the same pair of scissors had been used to cut the nails of the second murder victim. Although the scissors had been cleaned between uses, I couldn't help but wonder whether sufficient genetic material had survived the cleaning process to transfer onto the second victim's nails and then produce a DNA profile in the subsequent analysis.
In 1997, the time of the mystery murder, DNA profiling was only a few years old and, as I was about to discover, the technology was improving so quickly that previously unforeseen problems were beginning to occur.
I arranged for the nail scissors from the mortuary to be analyzed and discovered not two but three separate DNA profiles were present. Further examination found DNA contamination on several other mortuary instruments but it was only ever going to present a problem when it came to fingernail scissors.”

This discovery led to a change in the methodology in forensic science then onwards. “I immediately sent out an urgent memo to all coroners, mortuaries and forensic pathologists in the country, highlighting the problem and suggesting that, in the future, all nail clippings should be taken with disposable scissors and that the scissors should then be placed in the evidence bag with the nail clippings to confirm they had only been used once. It's a system that remains in place to this day” says Dr Silverman.

So, in the end, the theories that a ghost was the murderer, or that the criminal travelled in time and committed murder before her own death, or that the dead woman mysteriously came to life in the mortuary and scratched another dead body before dying again were all thrown away. An innocent pair of scissors gave sleepless nights to some of the best crime investigators in the world and almost created a story which would probably have gone down as one of the most popular unsolved mysteries of all time.