She Wore the Badge for 23 Years After the Murder: How DNA Exposed Former LAPD Detective Stephanie Lazarus

#KRITICIZM - For more than two decades, the murder of Sherri Rasmussen remained unsolved while the woman eventually convicted of killing her continued building a career inside the Los Angeles Police Department.

It wasn’t until advances in DNA testing allowed cold-case investigators to revisit a crucial piece of evidence that the investigation took an extraordinary turn—straight toward one of the LAPD’s own detectives.

The 1986 Murder of Sherri Rasmussen

On February 24, 1986, 29-year-old Sherri Rasmussen, a nursing director, was found dead inside the Van Nuys townhouse she shared with her husband, John Ruetten.

Rasmussen had been severely beaten and shot three times in the chest. Evidence inside the home showed that a violent struggle had occurred, and investigators collected saliva from a bite mark on Rasmussen’s arm.

Police initially pursued the theory that Rasmussen had interrupted burglars.

Her BMW was missing, and items inside the home appeared to have been disturbed. Investigators focused on the possibility that male burglars were responsible, but the theory ultimately led nowhere.

Her Family Had Pointed Police Toward Stephanie Lazarus

Rasmussen’s family believed investigators were overlooking another possibility.

Before marrying Rasmussen, Ruetten had been romantically involved with Stephanie Lazarus, who was an LAPD officer.

Rasmussen’s father, Nels Rasmussen, later said he repeatedly urged investigators to examine Lazarus and told them about troubling confrontations his daughter said she’d had with her. The original lead detective disputed parts of the father’s recollection, but confirmed that he never interviewed Lazarus and continued believing a burglary was responsible for the killing.

The case eventually went cold.

Meanwhile, Lazarus remained with the LAPD.

She Became an LAPD Detective

Over the following decades, Lazarus advanced through the department.

She eventually became a detective and received a specialized assignment investigating art theft and fraud. By the time investigators began looking seriously at her, she had spent roughly a quarter-century with the LAPD.

Then forensic science changed everything.

The saliva collected from Rasmussen’s bite wound had been preserved. Years after the murder, DNA testing established an important fact: the saliva belonged to a woman.

That finding undermined the original theory involving male burglars.

Cold-Case Detectives Start Over

In 2009, LAPD cold-case investigators reopened Rasmussen’s murder.

Rather than relying on assumptions made in 1986, detectives essentially began investigating the case again. They interviewed Ruetten and Rasmussen’s parents and learned more about Lazarus’ past relationship with Ruetten.

Lazarus suddenly became a serious suspect.

But investigators needed her DNA for comparison.

Because she was still an LAPD detective, the investigation was handled discreetly. Undercover officers followed Lazarus until they were able to recover an item she had discarded after using it. Investigators obtained her saliva from the discarded material and compared its DNA profile with the evidence preserved from Rasmussen’s bite wound.

It matched.

At a preliminary hearing, an LAPD forensic specialist testified that the statistical probability of the crime-scene DNA belonging to someone other than Lazarus was extraordinarily remote.

Arrested Inside the Department She Had Served

Detectives couldn’t simply approach Lazarus as they might an ordinary suspect. She was an armed colleague working inside LAPD headquarters.

In June 2009, investigators used a ruse to bring Lazarus downstairs to an interview room in the department’s jail area, where she had to surrender her weapon before entering.

During the recorded interrogation, detectives gradually began asking about Ruetten, Rasmussen and the events surrounding the 1986 murder.

After the interview ended, Stephanie Lazarus was arrested.

It had been approximately 23 years since Sherri Rasmussen was killed.

Prosecutors Build Their Case

DNA was the centerpiece of the prosecution, but it wasn’t the only evidence presented.

Prosecutors argued that Lazarus had been deeply upset by Ruetten’s decision to marry Rasmussen. Jurors heard testimony about Lazarus’ reaction to the relationship and were shown writings prosecutors said demonstrated her feelings toward Ruetten.

They also presented firearms evidence. The bullets recovered from Rasmussen were consistent with ammunition issued to LAPD officers at the time, and prosecutors noted that Lazarus had owned the type of .38-caliber revolver that could have fired them. Lazarus reported that gun stolen about two weeks after Rasmussen’s killing.

Her defense challenged the reliability and handling of the decades-old physical evidence and disputed the prosecution’s interpretation of the case.

Ultimately, the jury sided with prosecutors.

26 Years Later, a Guilty Verdict

On March 8, 2012, a Los Angeles jury convicted Stephanie Lazarus of first-degree murder.

The verdict came more than 26 years after Sherri Rasmussen was killed.

Two months later, Lazarus was sentenced to 27 years to life in prison.

The conviction finally answered the central question that had haunted Rasmussen’s family for decades.

But it also left another question: Why wasn’t Lazarus thoroughly investigated in 1986 when Rasmussen’s family was raising concerns about her?

The LAPD itself acknowledged after Lazarus’ arrest that it needed to examine how the original investigation had been handled.

The Evidence That Waited More Than Two Decades

Perhaps the most remarkable part of the case is that the evidence capable of breaking it open had been collected on the day of the murder.

A bite mark.

A saliva swab.

In 1986, forensic technology couldn’t tell detectives whose DNA was on that evidence. Decades later, it helped investigators identify the killer and ultimately helped prosecutors secure a conviction.

For 23 years after Sherri Rasmussen’s death, Stephanie Lazarus remained free and continued working in law enforcement.

But the evidence remained too.

And when science finally caught up with it, a murder that had been cold for decades led investigators directly back inside their own police department.