The answer to the mystery of who was behind the 1986 killing of Sherri Rasmussen was, in hindsight, abundantly clear.
Then-Los Angeles Police Department officer Stephanie Lazarus had beaten and shot the 29-year-old nurse three times in her home in a gated complex in the California neighborhood of Van Nuys, a jury would determine after several days of deliberations.
Rasmussen had been married for three months to John Ruetten, a man with whom Lazarus had long been involved in an on-again, off-again relationship. And before she was killed, Rasmussen had spoken of several run-ins she had with Lazarus that left her unnerved.
“As the evidence in the case came out, it wasn’t really a whodunit,” Matthew McGough told InsideEdition.com.
His book, “The Lazarus Files: A Cold Case Investigation,” examines the case and the investigation that followed, noting that while the person responsible for Rasmussen’s death may be behind bars, there’s still far more left to be uncovered. And that’s because Lazarus’ conviction came 26 years after she cut Rasmussen’s life short.
“There is a lot of unanswered questions,” McGough said. “We know who killed Sherri, but we don't know a lot about how Stephanie got away with it. And most importantly, no one has been held accountable for any of the mistakes that allowed a police detective to get away with a cold-blooded murder for more than 20 years.”
The initial probe into the murder of Sherri Rasmussen appeared to be well-intended.
Investigators surveying the scene believed it to be the work of a botched burglary. Rasmussen’s home was ransacked and her BMW was missing.
A nearby home was burglarized not long after Rasmussen’s killing and officials surmised the two incidents were connected, and though they suspected two unidentified Latino men as being behind both cases, no arrests were made.
Rasmussen’s family wasn’t as convinced.
Her father, Nels Rasmussen, told police his son-in-law’s ex had approached his daughter while she was working and told her, “If I can’t have John, no one else will.” It was one of several exchanges Sherri had with Lazarus that left her concerned.
But Nels’ theory was cast aside, according to his attorney, who would years later tell reporters, “He was always diverted. He was told repeatedly that he’d been watching too much TV.”
The lead detective at the time has denied ever being told about a potentially jealous ex-girlfriend.
“At the time, LAPD detectives insisted that it was a burglary gone wrong,” McGough said. “But the truth was actually more sinister.”
Lazarus’ life was the best cover a murderer could ask for.
She majored in political science at the University of California at Los Angeles, and after graduating, applied to the city’s police academy.
A natural athlete and fitness buff, Lazarus successfully completed training became a uniformed officer in 1983.
She would go on to create for herself a lustrous career with the LAPD, rising through the ranks and earning commendations along the way.
“She worked several sensitive assignments, including in internal affairs,” McGough said. “She worked at Van Nuys division — which is where the murder occurred — two separate times, in the 1990s. And without question, during those time periods, she had unfettered access to all of the case files involving the unsolved murder of Sherri Rasmussen.”
But regardless of her feats in law enforcement, Lazarus remained steadfast in her interest in Ruetten.
The pair met in college and became friends who occasionally had sex.
Though it appeared Lazarus was more serious about Ruetten than he was about her, they remained close for years. Photos obtained by McGough in his reporting showed Ruetten attended Lazarus’ graduation, and detailed diary entries Lazarus kept after becoming a police officer noted she had forged relationships with several of his family members.
"I wish it didn't end the way it did, and I don't think I'll ever understand his decision,” she wrote in a letter to his mother after learning of his engagement to Sherri.
After learning Ruetten was to be married, Lazarus visited him at his home. Rather than turn her away, he welcomed her inside and they ultimately had sex.
Ruetten would testify years later that he slept with Lazarus “to give her closure,” but it appeared the gesture did not work. Throughout her engagement and brief marriage, Sherri noted Lazarus stopped at her and Ruetten’s home several times, and before being killed, she told her father she feared she was being stalked.
Sherri’s fears were not unfounded.
On Feb. 24, 1986, her battered and bloody body was found on the floor of her living room.
In addition to being beaten and shot, Rasmussen had suffered a bite to her arm during the vicious struggle.
It would become the key to solving her murder.
Sherri’s family anguished and Lazarus’ career thrived in the years that followed.
“Stephanie has never spoken publicly about what influence she may have exerted over the case, what she may have done, but without question, she had the opportunity to remove materials, documents from the casebook, that may have implicated her,” McGough said.
In more than one instance, evidence connected to Sherri’s case appeared to have grown legs, including some that vanished at a time when it was apparently needed the most, he said.
“There’s a lot of evidence in the case that went missing over the years, including trace evidence collected from Sherri’s body that was inexplicably checked out from the coroner’s office by a LAPD detective in the early ‘90s, and was never seen again,” McGough said.
“That occurred shortly after Sherri’s parents requested the LAPD perform a DNA analysis, and that trace evidence was exactly the kind of evidence that would be useful for DNA testing.”
But that was not the only evidence investigators could make sense of using DNA technology, as police in 1986 took a swab of the bite wound Sherri suffered during the attack.
Justice was elusive and delayed, but it finally became tangible years later when the mechanisms to analyze the DNA were developed.
“The tide began to turn in the early 2000s, when a DNA analyst named Jennifer Francis performed DNA testing, and determined that it was female DNA on Sherri's body,” McGough said.
That information would lead homicide detectives in the Van Nuys division investigating the cold case to Lazarus. After eliminating four other possible women as the murderer, police set out to retrieve Lazarus’ DNA all while keeping the seasoned cop from knowing she had risen to the top of the suspect pool.
Police tailing Lazarus one day snatched a cup from which she had been drinking while off-duty and running errands.
It came back a match.
“The same unit that had failed to solve the case 20 years earlier, picked up this dormant cold case, and within a few months, had put together a case implicating one of their own colleagues, one of the most shocking outcomes of a murder investigation in the history of the LAPD,” McGough said.
Stephanie Lazarus was arrested in June 2009.
Then a high-ranking detective working art theft cases as part of the LAPD’s commercial crimes division, investigators at first tread lightly in approaching Lazarus about Sherri’s murder.
Under the guise of needing her help with a different case, investigators asked Lazarus to sit down with them in a building where all firearms must be surrendered upon entering.
About two minutes into their conversation, police asked Lazarus if she knew Ruetten.
“Yeah, we were very close friends, what’s this all about?” Lazarus asked, footage of the interrogation showed. “It was kind of a weird relationship. We dated, I can’t say that he was my boyfriend, I don’t know that he would consider me his girlfriend … it just didn’t work out.”
“Do you know what happened to his wife?” a detective could be heard asking.
“Yeah, I know she got killed,” Lazarus replied.
She claimed to not be able to remember how many times or under what exact circumstances she and Sherri may have met, but said they may have spoken about Ruetten.
“I think, you know, at one point, I mean, he may have been dating her … maybe he was married, I don’t even remember,” she said. “And I’m like, 'You know what, why are you calling me if, you’re either dating her or living with her or married to her, 'cause I honestly don’t remember the time frame.' And I’m like, 'Come on, knock it off.'”
But her explanations and denials fell on deaf ears, as officials had already planned to arrest her the moment she ended the interview, and when the questions concerning Lazarus’ involvement in Sherri’s death became more pointed, she became defensive.
“If you guys are claiming that I’m a suspect, then, I’ve got a problem with that, OK?” Lazarus said. “So, if you’re doing this as an interrogation, you’re saying, hey, I’m a suspect … now you’re accusing me of this? Is that what you’re saying?
“Now it almost sounds like you’re trying to pin something on me … I can’t believe this,” she continued.
Lazarus ended the interview and walked out of the room, where a pair of handcuffs were waiting.
Footage of the interrogation showed she returned to the room several minutes later, this time with her hands bound behind her back.
“This is absolutely crazy. This is insane. Crazy,” she said, before being read the Miranda warning.
News of Lazarus’ arrest spread like wildfire and left many stunned. Among them were McGough, who a year earlier had tapped the detective’s expertise for a story.
“I was interested in writing about art theft, which was Detective Lazarus's last assignment before she was arrested for murder,” McGough said. “Stephanie was professional, cordial. I obviously had no reason to suspect that she might be hiding a horrible secret, that she had committed a murder more than two decades earlier and gotten away with it.”
At the time of Lazarus’ arrest, McGough was working as a writer for “Law & Order,” but the story behind the scenes interested him far more than any salacious details that could work their way into an episode of prime-time drama.
“I wanted to know what really happened,” McGough said. “I was intensely curious. … How she got away with it, that’s what I really wanted to know.”
McGough spent the next decade reporting out the story, first in an award-winning article, “The Lazarus File,” on the case in June 2011 and then in the book, “The Lazarus Files: A Cold Case Investigation,” in April 2019.
By speaking with Sherri’s loved ones, law enforcement authorities, attending court hearings and combing through court records, which included Lazarus’ diary entries and correspondence, McGough paints an engrossing picture of what led to the 1986 murder.
“At the time I started, I never envisioned that I would be able to obtain such granular information about what had happened,” McGough said.
McGough also makes clear in the 608-page book what exactly those who loved Sherri lost when she was killed.
“It was very important to me that I present Sherri not just as a victim, but as a human being,” he said. “Sherri was really a remarkable person.”
She was a beloved daughter, sister and friend who was preternaturally attuned to others’ wants and needs. Astoundingly driven, Sherri skipped numerous grades in school, graduated college at the age of 16 and rose quickly in her career as a nurse.
“She had a drive to work in nursing and to really revolutionize the field of nursing,” McGough said.
She was devoted to her husband, whom she fell hard for and with whom she was excited to begin a family.
“And, you know, her life was cut off in its prime,” McGough said.
Lazarus was found guilty of first-degree murder in March 2012 and was sentenced to 27 years to life in prison. She will be eligible for parole in 2039.
“Stephanie continues to insist on her innocence, although she's convicted, and all of her appeals have been denied,” McGough said.
It’s unclear what if any reaction the LAPD will have to McGough’s book.
He noted that he sent it to numerous law enforcement authorities and knows “people within the department are reading it,” but so far has not been contacted by anyone in an official capacity.
In 2010, the Rasmussen family filed a lawsuit against the LAPD in 2010 over its handling of the case, but it was dismissed because the expired statute of limitations.
“After Stephanie was arrested, the Rasmussens publicly alleged a cover-up, and requested the LAPD do an investigation of how one of their own detectives got away with murder for so long,” McGough said.
According to McGough, the LAPD's top brass at the time promised to further investigate. "But one of the things that I learned in the course of reporting my book is that the LAPD never did any investigation of what went wrong," McGough said.
When reached by InsideEdition.com, the LAPD had no comment about the assertions made by the author and the Rasmussens.
“I think time will tell what sort of impact the book has on the LAPD,” McGough said. But one thing remains, to McGough, crystal clear: “This story is not finished.”