Los Angeles ( CNN ) -- A California judge sentenced a retired Los Angeles Police detective Friday to 27 years to life in prison for murdering her ex-boyfriend 's wife in a jealous rage more than two decades ago . Stephanie Ilene Lazarus , 52 , was convicted of biting and shooting Sherri Rasmussen , 29 , in her townhouse in the Van Nuys neighborhood of Los Angeles in 1986 . Lazarus , who rose through ranks of the Los Angeles Police Department and became a veteran art theft detective , could be eligible for parole in 22 years . Los Angeles Superior Court Judge Robert Perry gave Lazarus credit for time served in jail since her arrest at LAPD headquarters in June 2009 . A jury convicted her in March of first-degree murder . Friday 's sentence was the maximum under state law , prosecutors said . Lazarus was charged with staging the crime scene to look like a burglary gone bad , and police long believed that Rasmussen was the victim of two male burglars . The 1986 case went cold for years . Then it was reopened in 2004 and again in 2009 , when DNA from a bite mark on the victim 's arm came back as a match to the detective . When Lazarus became a suspect , homicide detectives faced `` special challenges as Lazarus ' office was located next door to the detectives who were now investigating her , '' police said in a statement in March . Rasmussen , a hospital nursing supervisor , was the new bride of John Ruetten , who had been Lazarus ' college sweetheart . Married for just three months , Ruetten found his wife 's body when he returned home from work . Rasmussen was brutally beaten and shot three times in the chest , authorities said . Los Angeles County deputy prosecutors Shannon Presby and Paul Nunez submitted a written statement to the court prior to the sentencing , according to the prosecutor 's office . `` Lazarus has never taken responsibility for her acts , '' the prosecutors wrote . `` Lazarus has never expressed any regret or remorse for her actions . Lazarus ' profound narcissism led her to kill and continues to motivate her denial of responsibility . This unrepentant selfishness poses a real and significant danger to any person whose interests conflict with Lazarus ' egotistic desires . '' Before the sentencing Friday , Rasmussen ' mother , Loretta , told the court that her family has endured `` extreme pain '' over her daughter 's murder . `` Every day we miss her laughter and her love , '' the mother told the judge . In his remarks to the judge , a tearful Ruetten said Rasmussen was `` just trying to save her own life '' on the day of her murder . `` I just ca n't bear thinking about these moments , '' Ruetten told the court . After the sentencing , Lazarus , manacled and dressed in a jail jumpsuit , waved and smiled to an apparent loved one in the courtroom gallery as she was escorted back to jail , carrying a folder . Following Lazarus ' conviction in March , Los Angeles Police Chief Charlie Beck said the case was `` a tragedy on every level . '' `` Not only did the family of Sherri Rasmussen lose a wife and a daughter , a life that can never be returned , but also the LAPD family felt a sense of betrayal to have an officer commit such a terrible crime , '' Beck said in a written statement . `` I am also sorry it took us so long to solve this case and bring a measure of justice to this tragedy , '' he said . Rasmussen , director of nursing at Glendale Adventist Medical Center , was a tall , athletic 29-year-old with a pretty smile . At the time of the slaying , Lazarus was in her second year with the Los Angeles Police Department . The killing occurred on February 24 , 1986 , a Monday . Lazarus had taken the day off ; Rasmussen had called in sick that morning . Authorities estimate she died before lunchtime . Prosecutors argued that Lazarus was in love with Ruetten and distraught when she learned he married someone else . During the trial , Ruetten testified he casually dated Lazarus after college , but he never considered her a girlfriend and dated other women while seeing her . Lazarus eventually married a Los Angeles Police detective and the couple adopted a daughter . According to prosecutors , the key to unlocking Lazarus ' dark secret lay for years on the back shelf of an evidence freezer in the coroner 's office . In a vial inside a sealed evidence envelope was a cotton swab . On that swab , prosecutors say , was DNA taken from saliva from the bite wound on Rasmussen 's left forearm . Testing in 2005 revealed the assailant was a woman . Some detectives , however , clung to the burglary theory and focused their inquiries on known female prowlers . But from the beginning , the victim 's family had pointed to an ex-girlfriend of Ruetten 's who was a cop , and as the DNA testing advanced , undercover police followed Lazarus to a Costco store and retrieved a discarded soda from a trash can . Saliva traces from the straw matched the bite mark DNA , and she officially became a suspect . Lazarus was confronted , and another sample was taken from her shortly before her arrest . Tests revealed the DNA found in the bite mark on Rasmussen 's left forearm belonged to Lazarus . Deputy Assistant District Attorney Presby told jurors during the trial that the chance of the killer being anyone else is `` one in 1.7 sextillion . '' To avoid botching an undercover investigation of one of their own , LAPD officials carefully devised a plan to arrest Lazarus . On June 5 , 2009 , Detective Daniel Jaramillo from the department 's robbery-homicide division approached Lazarus at her desk in the department 's headquarters and asked her to accompany him downstairs to the department 's jail facility , where she would not be able to bring her gun . He told Lazarus he needed her help interrogating a man who claimed to have information on stolen art , Lazarus ' specialty in the detectives unit . A nearly hour-long recorded interview followed . After one of the detectives alludes to the evidence that implicated her in the killing , Lazarus said , `` Am I on 'Candid Camera ' or something ? This is insane . This is absolutely crazy . This is insane . '' Minutes later she walked out of the interview room , only to be stopped , handcuffed and told she was under arrest in the murder of Sherri Rae Rasmussen . Lazarus 's attorney , John Overland , has argued in court that the crime scene evidence from 1986 was mishandled and tainted years ago and could n't be trusted . CNN 's Ann O'Neil contributed to this report .
NEW : `` I just ca n't bear thinking about these moments , '' the victim 's husband tells the court . Former detective Stephanie Ilene Lazarus , 52 , could be eligible for parole in 22 years . She was convicted of shooting and killing Sherri Rasmussen , then 29 . Rasmussen was the new wife of Lazarus ' ex-boyfriend .