Forensic Magazine - Handheld Wet Vac System Snags Decades Old DNA

Forensic Magazine - Handheld Wet Vac System Snags Decades Old DNA

Red Shoe

By Seth Augenstein Published In Forensic Magazine August 17 2016

The girl was found beaten to death on the jagged banks of the Provo River in 1995. The murder weapon was a bloody rock found next to the body. Investigators were fairly confident the side of the stone without the blood stains had been where the killer gripped the weapon. But swabbing for DNA turned up nothing of use.

The trail went cold.

The murder of Krystal Beslanowitch, and the bloody stone used to perpetrate the crime, remained on a shelf at the Wasatch County Sheriff's Office for 18 years. Though they knew there could be invisible trace evidence on the murder weapon that could produce a breakthrough, there was no way to collect it and test it.

That changed in 2013. Using a wet vacuum collection system called the M-Vac, forensic analysts pulled enough microscopic trace DNA to paint a full genetic portrait of the murderer. The alleged killer, Joseph Michael Simpson, was identified, investigated, charged, and arrested. His trial is scheduled for later this year.

The M-Vac was the breakthrough in that case – and in a growing number of tough investigations where traditional swabbing and testing have not been enough.

It's a system that brings a potential revolution in the collection of DNA – even in cases where multiple attempts at swabbing key surfaces have turned up no results. The tool has slowly been adopted by local and state agencies across the country, compiling a list of dramatic breakthroughs in cold cases and other stubbornly-unsolved homicides and sexual assaults.

“It could potentially be a real game changer,” said Christopher Hopkins, the director of the forensic science graduate program at UC Davis, who is also on the company's board of advisers.

“The forensic community needs to know about this tool,” said Sgt. Stewart Mosher, of the Broward County Sheriff's Office in Florida, a frequent user of the M-Vac.


The technology works like a “mini hurricane” of sterile solution combined with vacuum pressure, according to Jared Bradley, the CEO of the Utah-based M-Vac Systems. It sprays the solution onto the subject surface, and then sucks the wet traces back into a container. The microscopic genetic material accompanies the flow of air and solution. The solution and DNA material is then run through a filter or a microcentrifuge.

The tool was originally developed by the late Bruce Bradley, a microbial scientist, to find food contamination. But it proved to be too sensitive in finding the most miniscule traces of potential pathogens.

There's no such concern with DNA, where more is almost always better. As much as 200 times more DNA can be taken from difficult locations, particularly porous surfaces that otherwise defy simple scraping or swabbing.

Another key advantage to the technology is the amount of area covered, forensic experts said. While swabbing can only do a few square inches of area, the vacuum can keep going for feet at a time – allowing DNA expects to test entire garments instead of just a small swath of the fabric.

“There is a limit to how much area you can swab with a single swab before it just starts to fall apart. There is no similar limit with the M-Vac,” said Suzanna Ryan, a forensic DNA expert, also on the company's board of advisers.

“Let's say you had a case where a victim was attacked in her bed and you know that the suspect grabbed the covers and pulled them off the bed,” Ryan explained. “To try to swab the entire bed cover would be extremely time consuming and expensive. The M-Vac could be used to wet vacuum the entire bed cover onto a single filter.”

Investigators use the M-Vac on the shoe of Annie Kasprzak, found slain on the banks of a Utah river in 2012. DNA evidence obtained by use of the M-Vac eventually led to a guilty plea of the killer in February 2016. (Courtesy of M-Vac)


Like that rock along the Utah river, M-Vac has pulled crucial evidence from surfaces that have otherwise defeated traditional cutting, swabbing, taping and scraping. Clothing, ropes and restraints, rocks and bricks, porous and smooth surfaces, and items soaked in blood or water can all give up their secret traces to the suction of the M-Vac, according to survey of case histories.

The first high-profile breakthrough was the arrest in the Beslanowitch case, with the bludgeoning rock.

Another headline-grabbing Utah case, the 2011 death of Uta von Schwedler, showed a different side of the technology. Von Schwedler was found in her bathtub, blood full of Xanax and her limbs covered in cuts, her death at first looking like a suicide. Her bedding showed a Y-STR profile that matched her ex-husband – but also the same as the couple's two male children living in the house. The M-Vac made the breakthrough again. A large sweep of the pillowcase produced the full DNA profile of the ex-husband, John Brickman Wall, who was convicted on a murder charged last year.

Other cases have shown the adaptability of the machine.

A shirt used to tie the legs of a man who was put into a car and then pushed off a cliff in the United Arab Emirates was combed for DNA using M-Vac. Despite inconclusive swabbing results, the vacuum produced enough genetic material for four people: the man, his wife, and the two collaborators who helped her carry out the murder-for-hire plot. All three conspirators confessed to the crime.

A brick used to kill a person found in a field in China yielded the genetic profile to the M-Vac, which allowed a genetic match and a confession from the killer.

The water-logged underwear of a little girl led to the trace DNA that identified the man who raped and killed her.

Cold cases present a particular allure. DNA long undiscovered could lead to a dramatic reversal of fortune from within evidence storage, said Ryan. “I think that just about every cold case out there could potentially have an item of evidence that could benefit from sample collection with the M-Vac,” she said, adding that investigators would still need to be aware of potential contamination from years of evidence handling.


The most frequent user of the technology thus far is the Broward County Sheriff's Office in Florida. The first case the Broward detectives employed the technology was similar to the Beslanowitch case. A concrete block used as a murder weapon had stymied traditional DNA swabbing techniques, said Mosher, sergeant in the office. But the M-Vac extracted the breakthrough evidence in a single try.

Since acquiring the tool two years ago, 23 of the toughest Broward cases have resulted in 16 hits and case breakthroughs, according to Mosher.

“There's no silver bullet for every single case,” said Mosher. “But this is an awesome piece of equipment when you have literally exhausted all those basic techniques.”

WSP Swab Comparison 4

A DNA readout shows the increased accuracy of the M-Vac method, top, as opposed to the traditional swabbing, below, in a trace DNA case. (Courtesy of M-Vac)

The machine's main use so far is in homicides. But a special vented sampling head allows the tool to be used on human skin, potentially revolutionizing sexual-assault investigations where traces are left on the victim's body.

“A lot of times a sexual assault victim is blindfolded or knocked out. Forensic analysts would not swab a victim's whole body,” said Hopkins, the UC Davis forensic expert, a former FBI special agent. “But you can M-Vac someone's whole arm or leg in a matter of minutes.”

Broward County has acquired some of those special sampling heads for use with their machine, though they have not yet had to use it. The sheriff's office expects to add another M-Vac unit, due to its ongoing successes, Mosher said.

The machines has proven extremely cost-effective, the sergeant added. For The price tag for an M-Vac is $24,500 to begin, for a year's worth or more of cases. That first concrete-block murder case in Broward County had already run the sheriff's office more than $100,000 over the time-consuming, and ineffective, hours of swabbing. The M-Vac broke the case, for pennies on the dollar, Mosher said.

“It's well worth the taxpayers' money,” Mosher said.