Not long ago a good friend, who is also a detective in one of the largest sheriff offices in the US, described the desperate circumstances one of his cases was in and what he had to do in order to move it forward. A young woman had been brutally murdered by a heavy, blunt object and found in her yard along with tools that indicated the person who had killed her also planned on disposing of her body. Most likely the suspect had just run out of time or he would have competed his grisly intentions.

The detective and his team had a suspect under surveillance and based on all the circumstantial evidence they were confident the suspect had committed the heinous crime, but due to a lack of hard evidence, particularly DNA linking the suspect to the murder weapons, they were unable to file charges.   To make matters worse, the judge overseeing the investigation had given the investigators a time limit on how long they could keep the suspect under surveillance and that time was quickly running out.

How can touch DNA be effectively collected off of a rough and porous surface? That was the question that had to be answered. The swabbing technique had been ineffective despite multiple tries, and the other methods could not penetrate the hard, porous surface. The detectives knew the suspects DNA was likely on the object, but how to actually collect it off of the surface constituted a major problem.

Fortunately, the detective was doggedly determined, information is increasingly abundant and searchable, and even small businesses can have a big presence on the internet. He was able to find several articles on a new wet-vacuum collection device called the M-Vac System. Almost immediately he knew it was the only possibility for getting that DNA off of the evidence. That’s when he called me and we arranged to get an M-Vac System to him and help in the case. Within a relatively short amount of time the M-Vac had collected the touch DNA material off of the murder weapon, the lab had processed it and the suspect’s DNA profile was generated. Due to the hard work of the investigative team, that suspect is now off the streets waiting for trial instead of being out on the streets further terrorizing the community.

Not many people would dispute the power and the growing importance of DNA evidence in solving and prosecuting cases. On the Department of Justice’s website, it states “The past decade has seen great advances in a powerful criminal justice tool: deoxyribonucleic acid, or DNA.  DNA can be used to identify criminals with incredible accuracy when biological evidence exists.  By the same token, DNA can be used to clear suspects and exonerate persons mistakenly accused or convicted of crimes.  In all, DNA technology is increasingly vital to ensuring accuracy and fairness in the criminal justice system.” This statement is likely focused on the incredible advancements in the forensic labs and the overall awareness in the use of DNA evidence. By that same token, however, finding new ways to collect the DNA is equally important and should receive an equal amount of attention. The sensitivity of the lab equipment is 100% irrelevant if a sufficient quantity of DNA material doesn’t make it into the sample. Like my detective friend knew, if you can’t collect it, you can’t detect it, and that can make all the difference.  

Written By Jared Bradley

President M-Vac Systems

CASE SUMMARY

Case Synopsis:

An employee of a check cashing store arrived at work in the morning to open the store. Once inside he was confronted by two males at gun point. The two males were wearing gloves and their faces were covered. The suspects instructed the employee to open the safe and they retrieved the money and then fled.

Towards the rear of the store a rope was located hanging from the ceiling. Roof tiles had been removed and a hole had been cut through the roof. This location is where the suspects gained entry into the store. The suspects did not leave any evidence behind and no fingerprints were obtained due to the suspects wearing gloves.

Evidence Collected:

The white rope that hung from the ceiling to the floor inside the store was collected. Crime Scene swabbed the rope for contact DNA. These swabs were sent to the local lab where no DNA profiles were obtained by their procedures. The entire rope was then sent to DNA Labs International to use the M-Vac System collection method for contact DNA.

Laboratory Processing:

The entire length of the rope was processed with the M-Vac wet-vacuum collection system. The rope was coiled to provide for a wider surface for collection. The sterile surface rinse solution was sprayed down and collected from the course material. Then the liquid collected was filtered through a Nalgene Rapid-Flow Sterile Disposable Filter.

Once the filter was dry it was cut out from the container and prepped for DNA extraction. A Chelex extraction method was utilized and quantified with the Quantifiler® Duo DNA Kit. It was then amplified with Life Technologies AmpFℓSTR® Identifiler® Plus PCR Kit and analyzed on a 3130xL Genetic Analyzer.

Results:

The DNA profile obtained from this item indicates a mixture of at least four individuals contributing to a partial major male and minor DNA profile. The major DNA profile developed was sufficient for comparison purposes and CODIS entry. The current investigation is ongoing.