Las Vegas murder cracked with record amount of DNA

Stephanie Isaacson's case was cold for 32 years

Stephanie Isaacson’s case was cold for 32 years

The 1989 murder of a 14-year-old girl in Las Vegas was resolved by, experts say, using the smallest amount of human DNA in history to resolve the case.

Stephanie Isaacson’s murder has cooled to the point where new technology allows us to test what remains in the suspect’s DNA, the equivalent of only 15 human cells.

Police on Wednesday said they used genome sequencing and official genealogy data to identify the suspect.

Her suspected murder died in 1995.

“I’m glad I found them killing my daughter,” Stephanie’s mother said in a statement read by reporters at a press conference Wednesday.

“I never thought the case would be resolved.”

Thirty-two years ago, Stephanie’s body was found near the usual route to school in Las Vegas, Nevada. She was assaulted and strangled.

This year, police were able to take up the case again with donations from locals. They handed over the DNA samples left to Othram, a Texas-based genome sequencing lab that specializes in cold cases.

A typical consumer DNA test kit collects approximately 750-1,000 nanograms of DNA in a sample. These samples are uploaded to public websites that specialize in ancestors or health.

However, crime scenes can contain only tens to hundreds of nanograms of DNA. And in this case, only 0.12 nanograms (or about 15 cells worth) were available for testing.

Using public databases such as and 23andMe, researchers were able to identify the suspect’s cousin. Eventually, they matched the DNA with Darren Roy Marchand.

Merchandise DNA from the previous 1986 murder was still recorded and used to confirm the match.

He was never convicted of suicide in 1995 and died.

The genomic technology used to resolve the case is the same as that used to catch the infamous one. 2018 Golden State Murderer..

“This was a big milestone,” Othram CEO David Mittelman told the BBC.

“Accessing information from such a small amount of DNA really opens up opportunities for many other cases that have historically been considered cold and unsolvable.”

The company is currently working on an incident dating back to 1881.

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