In early June, Stephanie Lazarus appeared in a Los Angeles courthouse in an orange jumpsuit, accused of committing a murder decades earlier -- a stark contrast from the Los Angeles Police Department uniform she wore until just a few weeks ago.
Lazarus, now charged with capital murder, spent the last 25 years as a highly regarded detective with the LAPD.
"She had a good reputation, hard-working, very energetic," LAPD Chief Charlie Beck told ABC News, adding that nothing in Lazarus' job performance raised a red flag. "People ought to, to recognize that it's -- that there are people that can hold very, very dark secrets, and hold 'em very well."
Her alleged secret goes back 23 years, to the 1986 murder of a young woman named Sherri Rasmussen. Rasmussen, a 29-year-old nurse, had, at the time of her death, been married only three months to a man Lazarus had known since childhood and previously dated.
"Sherri was bludgeoned and then shot," Beck said. "Shot several times at close range in the chest. ... There was a struggle, there was a struggle that involved a lot of physical contact, including a bite."
"It was a real loss to everyone and to the nursing world," said Althea Kennedy, former vice president of nursing at Glendale Adventist, where she supervised Rasmussen. "Because I think she would have gone far."
Lazarus has pleaded not guilty to the charges.
At the time of the murder, police suspected two men linked to a residential burglary in Rasmussen's neighborhood. The suspects were never apprehended, and the case book was eventually closed.
"I don't think they viewed [Lazarus] as a suspect," said Beck. "I'm sure that, in her opinion, she had gotten away with murder."
Cold case detectives took a fresh look at Rasmussen's murder a few years ago as part of a routine review of unsolved crimes that predated DNA testing to see if there was any evidence that could be re-examined. In the Rasmussen case, the evidence included fluids connected to a bite mark.
DNA analysis of saliva from Rasmussen's bite wound showed the original theory of the culprit's identity was mistaken. The DNA didn't belong to a male burglar -- but to a woman.
"They started looking, to see if there was somebody in the victim's life, and this is going back 23 years, so you gotta re-, you know, you gotta reinterview everybody," said Beck.
Investigators developed a list of female suspects, and they eliminated them one by one, until they came to Stephanie Lazarus.
"We were very shocked, obviously. But, you know, our belief here is that we follow these cases where they take us. And if it goes to Japan, we go to Japan. If it goes across the hall we go across the hall," said Beck.
But Lazarus seemed like the most unusual suspect. Her life appeared to be idyllic. She married another detective, and together they have a 2-year-old daughter. A young cop at the time of Rasmussen's murder, Lazarus worked her way up the system from the night shift to a prestigious position at LAPD headquarters investigating art theft.
A top secret surveillance team trailed Lazarus as she went about her daily routine. When she discarded a plastic utensil or cup, they snatched it to test her DNA. Police say it matched.
Fearing their investigation would be exposed, they worked quickly to orchestrate Lazarus' arrest. The investigation played out less than 30 feet from where Lazarus herself worked.