Los Angeles ( CNN ) -- The prosecutor sounded like the narrator of a hard-boiled police drama as he carefully laid out pieces of the puzzle that led detectives to arrest one of their own in a 23-year-old cold case . `` A bite , a bullet , a gun barrel and a broken heart , that 's the evidence that will prove to you that defendant Stephanie Lazarus murdered Sherri Rasmussen , '' Deputy District Attorney Shannon Presby told jurors as an unusual criminal trial began this week in Los Angeles Superior Court . The trial promises to tell the story of a decorated female officer who rose through the ranks of the Los Angeles Police Department while allegedly hiding a dark secret : She was getting away with murder . Lazarus , now 51 and retired from the force , is accused of killing her college crush 's new bride in 1986 , staging the crime scene to make it look like a burglary . Yes , she was a police officer , but she did not kill in the line of duty , or to protect the public , Presby alleged . `` This killing was personal . '' Rasmussen was a tall , athletic 29-year-old hospital nursing supervisor with a pretty smile . She met a brutal end , beaten , bitten and shot to death in her townhouse in the suburban San Fernando Valley on February 24 , 1986 . She 'd also been tied up and hit over the head with a vase . To police , it looked like a burglary gone bad . Stereo components were stacked by the door and Rasmussen 's new BMW , an engagement gift , was missing . The case intrigues because it blends soap opera suds with `` CSI '' -style forensics -- including broken fingernails and a bite mark . It also promises to hold up a mirror to one of the nation 's most storied law enforcement agencies . `` Metaphorically speaking , this case is about the new LAPD investigating the old LAPD , '' said Andrew Blankstein , who has covered the department for the Los Angeles Times since the 1990s . `` This trial really traces the evolution of the LAPD and its approach to investigations , coupled with the revolutionary advances in technology . '' He added , `` There 's the old adage that the LAPD would never go after one of its own , but this case flies in the face of that . '' According to prosecutor Presby , the crime was all about a guy . Witnesses who knew them in college at UCLA will testify that Lazarus was smitten with John Ruetten , but he just was n't that into her . To underscore his portrayal of Lazarus as a woman obsessed , Presby displayed an old photograph found during a 2009 police search of the journals she 'd stashed in a footlocker at home . Taken at their college dorm 30 years earlier , it shows Ruetten sleeping with his back to the camera . He was wearing only white cotton briefs . Ruetten did care for Lazarus , Presby continued , but in his view they were just good friends -- with occasional `` benefits . '' Defense attorney Mark Overland told jurors there was much more to the relationship . The couple dated after college , went on trips and slept together `` many , many times . '' Lazarus thought it was serious and also got to know and love Ruetten 's mother and brother . She thought they had a future , the lawyer said . When she learned Ruetten was marrying someone else , Lazarus decided to lay her cards on the table . She told him how she felt . They slept together one last time , and then he told her he was going ahead with his marriage to Rasmussen , Overland said . `` She was tearful , '' he added . `` She was n't hysterical . '' A key part of the case involves a confrontation between Lazarus and Rasmussen at the hospital where Rasmussen worked , but Overland insisted his client was no stalker . By some accounts , Lazarus allegedly told her rival : `` If I ca n't have him , nobody can . '' While Overland acknowledged there was a meeting between the two women , he described it as more of a heads-up . The message from Lazarus , according to her attorney : `` Hey , if he 's dating you , you 'd better tell him to stop bothering me . He keeps calling me . Tell him to knock it off . '' At the time of the slaying , Lazarus was in her second year with the Los Angeles Police Department . The killing occurred on a Monday . Lazarus had taken the day off ; Rasmussen had called in sick that morning . Authorities estimate she died before lunchtime . Ruetten found the body when he came home from work after 6 that night . Wearing a red robe , pink T-shirt and black panties , Rasmussen was sprawled on her back on the living room floor . By all accounts , the grim find left Ruetten dazed and despondent . Lazarus was a newbie patrol officer when Ruetten broke up with her for good . She was hurt by his rejection , sure , but she moved on and prospered , Overland said . She made detective and met her husband , a fellow Los Angeles police detective , in 1993 , and they have a daughter . She was headed for the department 's internal affairs and its prestigious art theft detail . 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 . A sealed evidence envelope contained a vial . Inside that vial 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 . But still some detectives clung to the burglary theory and focused their inquiries on known female prowlers . 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 . How sure were they ? Presby said the chances of the killer being anyone else is `` one in 1.7 sextillion . '' That 's a 17 followed by 20 zeroes . Overland says the crime scene evidence from 1986 was mishandled and tainted years ago and ca n't be trusted . The envelope has been torn . Photos show the top of the vial poking through . And while the top of the envelope may have been sealed with red crime lab tape , the bottom was wide open . Overland quoted the crime lab 's supervisor , who observed : `` We 've got a problem . '' Hairs , fibers and fingerprints found at the crime scene ca n't be tied to Lazarus at all and have n't been matched to anyone else , Overland told the jury . The jurors listened intently Monday but did n't take many notes . As prosecutors set the scene with their first witnesses , the images projected on a large screen were jarring : A beaming bride in white appeared one minute , followed by an image of a bloodied corpse in a red robe , arms and legs stiffened with rigor mortis . Both photos were of Rasmussen , and they were taken less than four months apart . Her father , Nels Rasmussen , occasionally choked back sobs , and one of the victim 's sisters teared up at the sight of the bloodied face with one eye blackened and swollen shut . Sherri Rasmussen `` wore the white dress that the defendant felt was hers , '' Presby said . `` Four months after that marriage , Sherri Rasmussen was dead , her beauty disfigured , obliterated , blotted from existence . '' Lazarus , dressed in black for court , appeared pale and waxy as she jotted notes and whispered with her attorneys . During breaks , she waved at her husband , mother and brother , who were seated behind her . Presby reminded jurors what life was like in 1986 . Ronald Reagan was president . Bill Cosby had the top-rated television show . People played Pong and Asteroids and hardly anybody had a home computer . And few , except for scientists , had heard of DNA . The genetic testing that is now the `` gold standard of evidence , '' was yet to come , Presby reminded the jury . `` A tiny Stephanie Lazarus was hiding in the bite on Sherri Rasmussen 's arm , '' he said . The O.J . Simpson trial in 1994 and 1995 helped cement DNA as a household word . Ten years later , the Los Angeles Police Department launched its cold case squad , reopening hundreds of files to see , as Presby said , `` if there were more killers hiding on evidence shelves in coroners ' freezers . '' It will be up to eight women and four men to decide if Lazarus is one of them .
Trial of former Los Angeles police detective Stephanie Lazarus is under way . She is accused of killing her romantic rival ; murder case went cold for 23 years . The case blends soap opera suds with `` CSI '' -style forensics . It also promises to hold up a mirror to a storied law enforcement agency .