This from LAObserved via the LA Times:

Stephanie Ilene Lazarus, 49, was arrested this morning at Parker Center. Cold case investigation into the 1986 beating death of the wife of her ex-boyfriend led to Lazarus, and her DNA was secretly gathered last week to help make the case.

In a City News story, the head of the Police Protective League is also quoted responding to the news:

Paul M. Weber, president of the Los Angeles Police Protective League, said Lazarus’
arrest “is deeply disturbing to LAPD officers and the people of Los Angeles.”
“If convicted, the actions of one police officer should not tarnish the trust and
respect the public has for the more than 9,800 dedicated police officers who serve and
protect the community and its residents every day,” he said.

Here’s the LATimes story archive on the case.