LAS VEGAS (KTNV) -- The murder of a 14-year-old Las Vegas girl in 1989 has been solved, according to Las Vegas police.
Eldorado High School student Stephanie Anne Issacson left for school at approximately 6:30 a.m. on June 1, 1989. When she didn't return later that day, her father became concerned and contacted the school.
He found out that she never arrived that morning and reported her missing. Her body was later found in a desert lot near Stewart Street and Linn Lane. She had been sexually assaulted and strangled.
The Las Vegas Metropolitan Police Department says it received a donation from Las Vegas resident Justin Woo in November 2020 to be used for work on homicide cold cases with minimal DNA.
Issacson's case was chosen in January and a sample from the suspect was sent to a lab.
On July 12, 2021, Othram Labs advised Las Vegas police that with less than 120 picograms of DNA, less than 15 human cells, they were able to identify a suspect through a testing procedure called genome sequencing.
Through genealogical research, the suspect was identified as Darren R. Marchand, a Las Vegas area resident who committed suicide in 1995.
Before his death, Marchand was arrested in connection to the murder of Nanette Vanderburg in 1986. But, the case was dismissed because of a lack of evidence. A sample of his DNA from that case was compared to the sample from Issacson's case and it was a match.
Recently, investigators solved what is believed to be the oldest-known cold case in the U.S. using the same DNA sample method for the murders of a 16-year-old and 18-year-old in Montana.
Here is how that process works: Evidence from a case is sent to a lab for testing. Once a DNA sample is identified, investigators take it and put it into a genealogical database similar to 23andMe or Ancestry.com. Once a match, or in the Montana case, matches, come back, investigators treat them as leads and get to work.
In the Las Vega case, it is believed that the donor, Woo, is the same Justin Woo who is a local entrepreneur and angel investor. He launched a nonprofit that helps locals in need named Vegas Helps in December 2020.
Las Vegas police say that anyone who is interested in making a similar donation to help solve cold cases, they can do so by going to lvmpdfoundation.org and designating the donation to the “Homicide Cold Case.”
This story originally reported by Joyce Lupiani on KTNV.com.