On June 1, 1989, 14-year-old Stephanie Isaacson headed out on her morning walk to Eldorado High School. The Las Vegas teenager frequently took a shortcut through a vacant sandlot to get to school quicker. After school let out that afternoon, Stephanie’s father began to worry when she did not arrive home at her usual time. Upon calling the school in hopes of finding out where she may be, it was revealed that Stephanie never made it to school.
A missing person report was filed and law enforcement investigators then conducted a local search, canvassing the area around the typical route that Stephanie would take to school. Her body was found at a sandlot and investigators determined she had been sexually assaulted and strangled to death. Over the years, a lengthy investigation, spanning decades, ensued and all available investigative leads were exhausted. Stephanie's killer remained undiscovered.
In 2021, the Las Vegas Metropolitan Police Department teamed up with Othram to reexamine DNA evidence from the crime scene in hopes that advanced DNA testing might generate new leads in the investigation. Funding assistance was generously provided by Justin Woo, founder of the non-profit organization Vegas Helps.
Othram scientists used Forensic-Grade Genome Sequencing to build a genealogical profile from the remaining DNA evidence—only 120 picograms (or 0.12 nanograms) of DNA. This sets a new lower limit on the quantity of DNA required to build a genealogical profile for a suspect of a crime.
Through genealogical research, the suspect was identified as Darren Marchand, a Las Vegas area resident who committed suicide in 1995. Marchand had been previously arrested in connection to the murder of Nanette Vanderburg in 1986 but the case was dismissed. Marchand’s DNA from the case involving Nanette was compared to the DNA located in Stephanie’s case and it was a match.
*Stay tuned next week for more on this record case.
Republished courtesy of DNASolves/Othram. Photo credit: Othram.