LA Police Solve Tricky Murder Mystery with the Smallest DNA 

Las Vegas Police have smashed a record while using ancestry to find cold case suspects. The Vegas law enforcement claims to have solved the 1989 murder of 14-year-old Stephanie Isaacson using the smallest known volume of DNA. Officials have sent 0.12 nanograms of DNA samples, or about 15 cells, to Othram’s gene sequencing lab to help find a match. A typical home DNA testing kit collects at least 750 nanograms.Othram’s gene sequencing lab used the sequences to search through ancestry databases and identify the suspect’s cousin and find Darren Roy Marchand as the culprit.

The team confirmed the match by comparing the sample against Marchand’s DNA from an arrest for a 1986 murder case. Marchand was never sentenced and died in 1995.Las Vegas Police investigated after resident Justin Woo donated money to help law enforcement solve cases using small DNA levels. The investigation at Othram lab started on January 19th, but it wasn’t until July 12th that the company identified a suspect.

Othram lab chief David Mittleman characterized the effort as a huge milestone in a discussion. This could solve cold cases where the samples were previously thought too small to be usable. There are suspicions that law enforcement might overstep privacy when conducting these tests, and the Justice Department has given guidelines to prevent those kinds of abuses. While there’s no indication Vegas authorities crossed boundaries in the Richardson case, a much larger range of potentially solvable cases also widens the potential for more privacy violations.

Genome sequencing and genetic genealogy, the processes used to help identify Marchand, have assisted in successfully solving dozens of cold cases in recent years. The most high-profile was the 2018 identification of the Golden State Killer, who killed 12 people and raped 45 women across California between 1976 and 1986.