32-year-old Las Vegas homicide cold case solved, sets a new lower limit of DNADNA, or Deoxyribonucleic Acid, is the genetic material found in cells, composed of a double helix structure. It serves as the genetic blueprint for all living organisms. required for the genealogical profile.
As usual 14-year-old Las vegas teenager, Stephanie Isaacson went to school around 6 a.m. on June 1, 1989, through a vacant sandlot to get to her school, Eldora High School. However, when she did not arrive home at her usual time, it was revealed she never made it to school that day upon calling the 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 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.
Othram scientists used Forensic-Grade GenomeA genome is the complete set of an organism's genetic material, while genomics is the study of genomes, investigating their evolution, structure, and function. Sequencing to build a genealogical profile from a sample from the crime scene that included a small amount of DNA —only 120 picograms (or 0.12 nanograms) of DNA or less than 15 human cells. This sets a new lower limit on the quantity of DNA required to build a genealogical profile for a crime suspect.
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.
Through genome sequencing and “genealogy studies”, the laboratory has identified Darren R. Marchand as a suspect in the case. Marchand died by suicide in 1995, the Las Vegas Metropolitan Police Department (LVMPD) said.
Before his death, Marchand was wanted in another murder case. In a press release, the police department said that he was arrested “in connection with the murder of Nanette Vanderburg in 1986, but the case was dismissed”. However, police later said at a press conference that there was not enough evidence to make a charge in relation to the Vanderburg murder. Marchand’s DNA from the case involving Nanette was compared to the DNA located in Stephanie’s case, and it was a match.
Police said in a press conference it took about seven months to complete the test. It involves new technology – hence why samples were not tested successfully in the past.
NS Las Vegas Sun reports that other DNA samples were tested in 1998 and 2007 and uploaded to national databases – to no avail. Finally, new technology has set the game.
Source: Fry-electronics.com
Forensic Analyst by Profession. With Simplyforensic.com striving to provide a one-stop-all-in-one platform with accessible, reliable, and media-rich content related to forensic science. Education background in B.Sc.Biotechnology and Master of Science in forensic science.