On July 21, 2021, Darren Roy Marchand was identified as the lead suspect in the June 1, 1989 rape and murder of 14-year-old Stephanie Anne Isaacson in Las Vegas, Nevada. The case has been cleared by exception due to the death of Marchand.
When Isaacson did not return home from school that day, her father began to look for her. He discovered that she did not arrive at school that day, and phoned police. Isaacson’s body was found s short time later in a vacant lot about 1/3 of a mile from her school – a location that was on her usual route to school. She had been sexually assaulted and strangled to death.
A DNA profile was obtained of a suspect in 1998, and again in 2007. The 2007 sample was developed from semen found on Isaacson’s shirt. Othram began the FGG investigation in November of 2020. They needed to perform a new DNA analysis, but there was only about 120 picograms – about 15 individual cells – of DNA remaining. This is, to date, the smallest sample used to generate a forensic DNA profile, and “sets a new lower limit on the quantity of DNA required to build a genealogical profile for a suspect of a crime,” according to Othram. The FGG investigation was reportedly funded by a local business owner named Justin Woo.
Marchand had earlier been charged with the murder of 24-year-old Nanette Vanderburg in 1986. Vanderburg had also been raped and strangled. That case was dismissed due to a lack of evidence at the time. The DNA taken at that homicide has since been compared to Marchand, and he is determined to be the leading suspect in that case as well.
Marchand committed suicide in 1995, at the age of 29.
DNA samples of about 30 male suspects were taken as part of the investigation into Isaacson’s death over the years, all of whom were cleared of any involvement in the crime.
Bleakley, Caroline, and David Charns. “I-Team: Police Solve 1989 Cold Case Murder of 14-Year-Old Las Vegas Girl.” NBC 8 News Now, July 21, 2021. Accessed July 22, 2021. https://www.8newsnow.com/news/local-news/metro-police-to-give-update-on-32-year-old-cold-case-murder/.
DNA Solves.com. “Las Vegas Metropolitan Police Department and Othram Partner to Identify 1989 Murderer of Stephanie Isaacson.” DNASolves.com, July 21, 2021. Accessed July 22, 2021. https://dnasolves.com/articles/stephanie_isaacson_murder/.
Ford, Alexis. “Suspect in 1989 Slaying ID’d Using World’s Smallest Sample of DNA Evidence.” Las Vegas Review-Journal, July 21, 2021. Accessed July 22, 2021. https://www.reviewjournal.com/crime/homicides/suspect-in-1989-slaying-idd-using-worlds-smallest-sample-of-dna-evidence-2404059/.
News 3 Staff. “LVMPD Solves 32-Year-Old Cold Case Involving Homicide of Teen Girl.” NBC News 3, July 21, 2021. Accessed July 22, 2021. https://news3lv.com/news/local/lvmpd-solves-32-year-old-cold-case-involving-homicide-of-teen-girl.
Torres-Cortez, Ricardo. “DNA Testing Reveals Killer in 1989 Strangling of Las Vegas Schoolgirl.” Las Vegas Sun, July 21, 2021. Accessed July 22, 2021. https://lasvegassun.com/news/2021/jul/21/dna-testing-reveals-killer-in-1989-strangling-of-l/.