Las Vegas police solve an old murder case using record-low volume of DNA

Las Vegas police appear to have smashed a record while using ancestry to find cold case suspects. BBC News reports that Vegas law enforcement claims to have solved the 1989 murder of 14-year-old Stephanie Isaacson (pictured here) using the smallest known volume of DNA. Investigators sent just 0.12 nanograms of DNA samples, or about 15 cells, to Othram’s gene sequencing lab to help find a match. For context, a typical home DNA testing kit collects at least 750 nanograms.

Othram used the sequences to comb through ancestry databases and pinpoint the suspect’s cousin and identify 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 convicted and died in 1995.

Vegas police launched the investigation after resident Justin Woo donated money to help law enforcement solve cases using “minimal” DNA levels. The investigation at Othram started on January 19th, but it wasn’t until July 12th that the company identified a suspect.

Othram chief David Mittlemen characterized the effort as a “huge milestone” in a discussion with the BBC. This could theoretically solve cold cases where the samples were previously thought too small to be usable.

The breakthrough won’t necessarily thrill everyone, however. There have been concerns that law enforcement might violate privacy when conducting these tests, and the Justice Department has established guidelines precisely 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.