Stephanie Ilene Lazarus was born around 1960 and raised in California, United States. She graduated from the University of California, Los Angeles (UCLA) with a degree in political science and was a highly motivated individual who went on to join the Los Angeles Police Department (LAPD) in 1983. Lazarus excelled early in her law enforcement career, later earning a master’s degree in criminal justice from California State University, Los Angeles.

Lazarus was described by colleagues as intelligent, hardworking, and personable. During her time at UCLA, she had an intermittent romantic relationship with fellow student John Ruetten. Their relationship continued sporadically after college, but Ruetten eventually became engaged to a nurse named Sherri Rasmussen. While Lazarus appeared to move on publicly, she harbored private feelings of jealousy and resentment toward Ruetten’s new partner. Lazarus’s life remained professionally successful—she rose through the ranks of the LAPD, eventually joining specialized units such as the art theft division. By all outward appearances, she led an exemplary career in law enforcement and maintained a stable family life, having married a fellow officer and adopted a daughter.

On February 24, 1986, Sherri Rasmussen was found murdered in the condominium she shared with her husband, John Ruetten, in Van Nuys, Los Angeles. She had been beaten and shot three times. The initial investigation by the LAPD concluded that the murder was the result of a botched burglary, and the case eventually went cold due to a lack of leads.

In 2009, the case was reopened by LAPD detectives who re-examined the evidence using advanced DNA technology. A key piece of evidence was a bite mark found on Rasmussen's body, which had been swabbed during the initial investigation. The DNA from the bite mark was tested and matched to Stephanie Lazarus. Further investigation revealed that Lazarus had continued to express romantic interest in Ruetten even after his marriage to Rasmussen.

On June 5, 2009, Lazarus was arrested and charged with the murder of Sherri Rasmussen. The trial began in early 2012, during which the prosecution presented evidence of Lazarus's jealousy and her prior confrontations with Rasmussen. The defense argued that the case was circumstantial and lacked direct evidence linking Lazarus to the crime scene.

After deliberation, the jury found Stephanie Lazarus guilty of first-degree murder in March 2012. She was sentenced to 27 years to life in prison and is currently serving her sentence at the California Institution for Women in Chino.

In May 2024, the California Board of Parole Hearings revoked plans to release Lazarus on parole after hearing emotional testimony from family and friends of the victim.