Investigators found Isaacson dead and bludgeoned by the sandlot — she had been sexually assaulted and strangled, police said.
For 32 years, the case remained cold, despite failed attempts at matching the DNA found on Isaacson’s shirt. That is, until nine months ago, when a Texas lab offered to process a cold case with the Las Vegas Metropolitan Police Department using new technology. The test would be free, thanks to a donation from an anonymous benefactor.
In January, police sent the lab the remaining DNA from Isaacson’s case — the equivalent of 15 human cells.
On Wednesday, the police department announced it had successfully identified the suspect using the technology, setting a record for the least amount of DNA used to solve a case.
Police identified the killer as Darren R. Marchand. But there would be no arrest — Marchand died by suicide in 1995 at 29 years old.
“I’m glad they found who murdered my daughter,” Isaacson’s mother, who was not named, wrote in a statement read Wednesday by LVMPD Lt. Ray Spencer at a news conference. “I never believed the case would be solved.”
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.
In April 2019, investigators successfully employed the technology to solve the brutal 1972 murder of a 20-year-old woman in Washington state. The killer died by suicide in November before sentencing.
And in March, Colorado investigators arrested a man who allegedly kidnapped, assaulted and murdered two women in 1982. The case is ongoing.
Isaacson’s case goes back decades. On the morning of June 1, 1989, the 14-year-old used her usual shortcut to get to Eldorado High School, police said. Isaacson’s father grew concerned when she did not come home that afternoon.
He contacted school officials to find out if they knew where his daughter was, but they said she wasn’t at school that day, according to police. He then called Isaacson’s friends, who also said they didn’t see her that day.
Soon after, Isaacson’s father called police and reported her missing. What followed was an aggressive air and ground search, law enforcement said.
At about 8:40 p.m., investigators spotted several of Isaacson’s school books and belongings in a “desert area” near her home, police said. Search parties then began scoping out the area. They found the girl’s body about 25 yards off the trail she normally took while walking to school.
An autopsy found that Isaacson had “significant blunt force trauma injuries and that she had been sexually assaulted,” Spencer, the lieutenant with LVMPD, said at the news conference. The Clark County Coroner’s Office noted she died of strangulation.
In the years since Isaacson’s death, police said they identified several suspects. Investigators traveled to Washington state, Ohio and Texas to follow up on leads.
In 1998, the department’s forensic laboratory attempted to test the evidence for DNA using now-obsolete technology. It was unsuccessful, according to Kim Murga, the lab’s director. It tried again in 2007 and successfully obtained a DNA profile from semen found on Isaacson’s shirt. The team uploaded the DNA profile into an FBI database but never received a match.
This past November, Othram, a genome-sequencing lab specializing in assisting with cold cases, reached out to Murga’s team and offered its services using its new technology. Someone had donated money to the lab specifically to help solve one cold case with the LVMPD.
“Stephanie’s case was chosen specifically because of the minimal amount of DNA evidence that was available,” Spencer said.
Over the course of seven months, Othram worked to build a genetic profile from the DNA.
“The Othram genealogy team used the profile to develop investigative leads that were returned to LVMPD,” the Houston-based company said in a news release.
Marchand had a criminal history in the Las Vegas area, Spencer said. He was arrested in 1986 at the age of 20 and charged with fatally strangling 24-year-old Nanette Vanderburg in her home. The case was ultimately dismissed for lack of evidence. Marchand killed himself nine years later.
DNA testing was not available when Vanderburg was killed, but police compared the DNA from her case with that found in Isaacson’s case. It was a match, according to an LVMPD news release.
There is no way to know if Marchand knew Isaacson.
“It appears to be a random attack while she was walking to school,” Spencer said.
Although the police department has finally solved Isaacson’s case, her family is grappling with how to move on when no criminal action can be taken against the man responsible.
“It’s good to have some closure, but there is no justice for Stephanie at all,” Isaacson’s mother wrote in her statement. “We will never have complete closure because nothing will ever bring my daughter back to us.”