INDIANAPOLIS, Ind. (Nov. 10, 2015)– With the city’s latest crime wave, detectives are in overdrive trying to solve crimes. A local professor and research assistant may have cracked the case as it relates to DNA evidence at crime scenes.
Moments after a crime takes place, the forensics team is on the scene collecting key evidence to help them catch their suspect. They could be getting secondary or “touch” DNA that could help the innocent or let the guilty roam free.
“When you say this is touch DNA it’s suggesting someone touched that object. And that’s why their DNA is on there,” said Associate Professor Dr. Krista Latham, who directs the University of Indianapolis’ Molecular Anthropology Laboratory and oversaw the study.
The study was a project by graduate students Cynthia Cale and Madison Earll. It looked at secondary DNA– whether it can be transferred to objects from someone who never touched the smoking gun. During this study, subjects shook hands for two minutes then handled test knives. The results were shocking after they swabbed the object for DNA.
“In 85 percent of the samples in this particular study we detected DNA on the object from individuals who did not have direct contact with the object. Their DNA was transferred to the object by the person they had direct contact with,” said Latham.
This is all thanks to more advanced and sensitive technology that picks up on smaller samples of DNA, whereas years ago larger DNA samples were used. It’s a scary game changer for the way forensic evidence is processed and used in a courtroom.
“To be able to inform the analyst this is a possibility and when you go into court be prepared to answer questions about how DNA is transferred because a lot of times we don’t know how the DNA got there, when it got there, under what circumstances,” said Cale.
Researchers will now look at results of touch DNA for shaking hands for a shorter period of time and whether smooth or coarse objects make a difference. This study has gained international attention and will be published in the January issue of the Journal of Forensic Sciences with a paper titled “Could Secondary DNA Transfer Falsely Place Someone at the Scene of a Crime?”