Updated

A family’s worst fears came true on June 1, 1989, when 14-year-old Stephanie Isaacson did not return home from high school and her remains were found in a nearby field. 

Police determined at the time that she had been sexually assaulted and strangled, but the case to find the suspect went cold despite a decades-long investigation spanning multiple states. 

Now, due to advances in genetic genealogy and a generous donation, Las Vegas police were able to identify Darren R. Marchand as the suspect in Isaacson’s alleged murder. 

"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," Kimberly Murga, the head of the forensics lab at the Las Vegas police department, explained at a press conference Wednesday. 

"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."

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Marchand had been arrested three years before Isaacson was murdered in connection to the death of Nanette Vanderburg, but the case was dismissed. The DNA located in Isaacson's murder, seminal fluid found on her shirt, was matched to the DNA found in Vanderburg's murder. 

A suspect in 14-year-old Stephanie Issacson's 1989 murder was identified this month through advances in genetic genealogy.

A suspect in 14-year-old Stephanie Issacson's 1989 murder was identified this month through advances in genetic genealogy. (Las Vegas Metropolitan Police Department)

Othram Labs was able to connect the two cases and identify Marchand despite the fact that an incredibly small amount of DNA evidence, just 15 human cells, were available in Isaacson's case. Prior DNA testing in 1998 and 2007 failed to yield any results. 

"Stephanie’s case was chosen specifically because of the minimal amount of DNA evidence that was available," Lt. Ray Spencer said Wednesday. 

Marchand committed suicide in 1995, police said. 

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Issacson's mother said in a statement that she never thought the case would be solved. 

"I’m glad they found who murdered my daughter," the statement said. "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."