M-Vac system can recover DNA from porous rock interiors years after crimes were committed
A DNA retrieval system for rough surfaces is being examined for use by gardaí in the renewed Sophie Toscan du Plantier investigation.
Use of the M-Vac has already solved several cold-case killings in the US and brought perpetrators to justice.
The naked, battered body of 17-year-old Krystal Beslanowitch was discovered outside Salt Lake City, Utah, on a cold morning in December 1995, exactly a year before Ms Toscan du Plantier was murdered in very similar circumstances.
Ms Beslanowitch suffered at least 16 blows to her head with rocks. In 2013, 18 years later, new technology was used to extract DNA from the porous rock interiors.
The results provided 30 times the amount of DNA the original swabs had provided. In September 2016, Joseph Michael Simpson was found guilty of the murder and was sentenced to life in prison.
Jared Bradley, president of M-Vac Systems, said his company’s extractor device could vacuum up DNA like a carpet cleaner.
“Once you start getting into porous, rough, more difficult surfaces, then swabbing and other physical methods – even sponges – can’t physically get down into the nooks and crannies where the DNA material might be,” he explained.
A study by the University of Illinois, Chicago, determined that swabs lost between 60-80pc of the DNA material somewhere between location and processing in a lab. “If you can’t collect it, you can’t detect it,” Mr Bradley said. “Even though lab equipment is incredibly sensitive, if you can’t collect it on the front end, it doesn’t matter. You can’t produce something out of nothing.
“But every human sloughs off 400,000 cells per day. So in the process of that, even if they’re extremely careful, if they’re in a crime scene, they’re most likely depositing DNA somewhere.”
The M-Vac was designed to collect e-coli and salmonella in food cases, showing how exacting its function can be. It was only later discovered to produce impressive results in forensics cases.
The FBI tested the system on different substances and surfaces and discovered that, at a minimum, the M-Vac collected five times more than what swabbing was able to do. On some fronts, such as carpet, it was 180 times more effective.
In the case of Ms Beslanowitch’s murder, the M-Vac produced 42 times more DNA, and generated a clear profile of the perpetrator.
In another case, the system exonerated a man who was wrongly accused.
In 2010, a family of four from San Diego disappeared. Three years later, a man riding his motorcycle in the desert discovered two shallow graves – in each of which was an adult and a child. The murder weapon, a sledgehammer, was also found in one of the graves.
M-Vac produced profiles of two unidentified individuals from the graves, leading to the freeing of a man who had been accused of the killings.
In another case, a woman’s body was found in Florida, having been bludgeoned with a torn-away house step.
As with Ms Toscan du Plantier, her skull had been heavily damaged.
The French filmmaker was beaten to death with a rock in Toormore near Schull, Co Cork, on December 23, 1996.
“You can imagine how rough and porous those steps are,” said Mr Bradley. “So the swabbing was negative, but we flew down there with the system and produced a good DNA profile. So this guy is now in prison, and that’s a huge win.”
In the case of Sharon Shawn Meyers, whose body was found gagged and blindfolded in a bath in Salt Lake City, the police didn’t have any suspects – or any ability to get DNA off the blindfold or gag. But after 39 years, the M-Vac extracted cells from where the killer tied the gag knot. He turned out to be Patrick McCabe, the apartment manager.
“Any kind of evidence you’re having difficulty getting a profile from, whether it be the sticky side of tape, rocks, bricks, rope – if traditional methods are not solving it and not getting a good enough profile, then those are perfect candidates for the M-Vac system,” Mr Bradley added.