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Law enforcement technologyIdentifying the criminals among multiple DNA samples

Published 11 March 2011

Providing certainty without a reasonable doubt is not possible when the DNA at a crime scene comes from multiple sources; this happens in about one in ten cases, meaning that important evidence for putting a criminal behind bars is lost; a new technique takes the uncertainty out of DNA samples, when more than one person’s DNA fingerprint is in the mix

A new invention looks deeper into DNA to show with certainty whether or not a suspect was at the scene of a crime. It is news that will have cold case murder victims smiling in heaven.

Israeli scientists have found a way to identify DNA that would otherwise be inadmissible in court — when it comes from a sample of multiple people.

Although forensic DNA analysis is used in less than one percent of all criminal cases, it has helped convict suspects in some of the world’s most heinous crimes, including murder and rape.

Providing certainty without a reasonable doubt is not possible when the DNA comes from multiple sources at a crime scene. Israel21 reports that according to police officials in Israel, this happens in about one in ten cases, meaning that important evidence for putting a criminal behind bars is lost.

A new technique developed at the Hebrew University of Jerusalem by a professor and his student takes the uncertainty out of DNA samples, when more than one person’s DNA fingerprint is in the mix.

The results were published recently in Forensic Science International: Genetics.

While Professor Ariel Darvasi from the Department of Genetics does not focus on forensics in his day-to-day life, he decided to supervise Lev Voskoboinik’s research after hearing Voskoboinik lecture about the problem and declare that there was no solution. Voskoboinik works at the Israel Police Forensic Biology Laboratory and was looking to earn a second degree in DNA analysis.

Solving the unsolvable

The questions and problems I like best are where people think there are no solutions. I prefer to think about the problems as solvable - that was the starting point,” says Darvasi.

 

Primarily I am working in research related to human diseases, developing standards and research and have never been much into forensics,” he continues. “Forensics though was always a topic I found of interest and there are similarities due to the nature of my research.

Lev came to my lab with the intent of doing a Ph.D. I suggested that he do something related to his work.”

The two went through Voskoboinik’s day on the job, and it was only after listening to Voskoboinik present his work to the lab group that the idea surfaced.

In his lecture, Voskoboinik described one of the cases that are common at a crime scene - when blood from more than one victim gets mixed together. In this case, the crime was a murder