ROCHESTER, N.Y. – Timothy Williams is accused of raping and murdering 14-year-old Wendy Jerome in 1984 on Webster Avenue. It took years, and years of working the case to get anywhere. The case picked up momentum once technology advanced.

Investigators used what’s called Familial DNA testing to identify Williams as a suspect in the cold case, nearly 40 years later. It’s when you use a family tree to narrow down your leads, when DNA testing fails to provide a direct match.

“The familial DNA gets into taking a sample and seeing if you can identify a perpetrator’s relatives,” said Tully Rinckey attorney Peter Pullano.

Rochester Police investigators explained the concept back in the fall of 2020, when they made the arrest.

In this case, investigators uploaded a DNA sample from semen in the autopsy, to an FBI database system. The system compares data to various known offenders and anyone else who has voluntarily uploaded their DNA through other means.

The DNA can lead to partial matches, including siblings, children, or other relatives. Once the family tree is there, investigators narrow down their search.     

Pullano said it’s still a fairly new concept for New York State.

“You’re casting a wide net, you’re definitely going to be including innocent people in that part of the search,” he said. “By definition you’re not looking to pinpoint, you’re looking for relatives, you’re looking for other individuals.”

Investigators have testified in court about interviewing Williams when he was 20 years old, shortly after the homicide. Williams lived in the neighborhood of Jerome.

The details about any conversation with him, however, remain limited.

“The Rochester Police Department certainly was not sitting on this case,” said District Attorney Sandra Doorley. “It was always in the forefront, people were always investigating, people were always looking at other persons of interest, making eliminations.”

Pullano said the familial testing is used when direct DNA testing doesn’t find a match.

“One of the other things that’s happened now over the last decade or so, is so many people are voluntarily submitting their DNA for these genealogy studies, 23 and Me type things, that you can compare there,” he said.

The technology has been challenged in the courts, but recently, the court of appeals ruled it was constitutional.

Pullano said the technology has received some backlash by people who cite privacy concerns, but he does believe we’ll start to see more of it.

The Timothy Williams trial is one of the first in New York State to use familial DNA testing.

On Monday, the jury heard from investigators Paul Boccanino and CJ Dominic, who both worked on the case.