Then a 14-year-old high school student, Stephanie Isaacson worried her parents for not coming home on June 1, 1989. She was found lifeless in a field nearby.

At that time, authorities said that Isaacson was sexually assaulted and strangled but her perpetrator was not identified amid enormous investigation through decades.

But the alleged suspect behind the crime was now identified by Las Vegas police, through the help of genetic genealogy advances and a benevolent donation, as Darren R. Marchand.

“That testing consists of sophisticated DNA technology to identify thousands of different markers, to obtain genetic information associated with the killer in a homicide, an unsolved homicide, an unsolved sex assault, or even unidentified human remains,” Las Vegas police department’s forensics lab head Kimberly Murga told Wednesday’s press conference.

“Then that genetic genealogy information is subjected to genealogy evaluation, where an expert will evaluate vital records, identify information, and perhaps be able to bring that genetic information to a family tree in order to link a subject.”

Three years before Isaacson was murdered, Marchand had already been arrested over the death of a certain Nanette Vanderburg. His case in connection to Vanderburg, however, was dismissed.

The seminal fluid in Isaacson’s shirt, which was gathered for DNA to investigate her murder, has matched with the same fluid found in Vanderburg’s murder case.

The two cases were linked by Otham Labs and identified Marchand as the suspect in Isaacson’s case even with only 15 human cells in the DNA evidence. DNA testing was also done in 1998 and 2007 but to no avail.

“Stephanie’s case was chosen specifically because of the minimal amount of DNA evidence that was available,” according to Lt. Ray Spencer on Wednesday.

The police said Marchand killed himself in 1995, as reported by Fox News.

“I’m glad they found who murdered my daughter,” Isaacson’s mother said in a statement. “It’s good to have some closure, but there’s no justice for Stephanie at all. We will never have complete closure because nothing will ever bring my daughter back to us.”