Forensic DNA: If You Can’t Collect It, You Can’t Detect It
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.
Originally published at https://www.linkedin.com.