DNA test put on trial

It was a murder that vexed city police.

On a spring evening three years ago, Brent Wentworth was strangled in his apartment in a quiet residential area on Schenectady's North Side.

Wentworth, 41, described by family members as a hardworking man who suffered from schizophrenia, had no known enemies and appeared to be a victim of a random robbery. Detectives were stumped and ran short on leads, eventually going public with Wentworth's family, offering a $2,000 reward for help in what police leaders called a "difficult investigation."

As months passed with no arrest, forensic scientists in the case turned to a new technology to examine human residue found on an amplifier cord that detectives believe was used to strangle Wentworth. The computer-assisted technology, which has never been tested in a New York court, uses mathematical formulas to pinpoint individual human DNA on an item that may have been touched by many people.

The DNA samples found on the cord led police to their suspect, John Wakefield, a career criminal from Schenectady who prosecutors said knew the victim in passing. In December 2012, Wakefield, who was in state prison on unrelated charges, was indicted in Wentworth's murder.

Prosecutors allege Wakefield went to the victim's residence and killed Wentworth before stealing his belongings.

Defense attorney Fred Rench of Clifton Park characterized the DNA technology used to zero in on his client as "voodoo" and said he will challenge whether it should be allowed as evidence.

The software, which analyzes low-quality and mixed DNA samples, has been accepted as evidence at trial courts in Virginia, Pennsylvania and California, according to its developer, Mark Perlin of Pittsburgh, Pa. He said the method, known as probabilistic genotyping, was used to help identify victims of the 9/11 terrorism attack in New York City and will be implemented at the State Police crime lab in Albany.

Perlin, chief executive officer of Cybergenetics, which developed the technology, said the computer program analyzes the mixed samples to narrow the DNA of a single person from hundreds of thousands of potential matches.

Barry Duceman, director of biological science for the State Police lab, said law enforcement agencies are embracing the technology. Duceman, who also serves as an adjunct professor of biology and biomedical sciences at the University at Albany, said the software uses a statistical analysis to help scientists separate the DNA of people contributing to a mixture of samples on something like a door knob.

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DNA test put on trial