A former Los Angeles police detective who killed a romantic rival and hid the murder for more than two decades will not be released from prison — at least not yet, California parole officials decided this week.

In November, a panel of parole commissioners found that Stephanie Lazarus, 64, was suitable for release, but on Monday the state parole board voted to approve a motion saying that decision deserves additional scrutiny because it may have been “improvident.”

The board cited an April letter from California Gov. Gavin Newsom and referred the case to a separate “rescission” hearing to determine if the grant of parole was improper.

In the letter, Newsom said that as a prisoner Lazarus had an excellent disciplinary record and had sought to improve herself. Yet she evaded justice for more than two decades in the 1986 murder of Sherri Rasmussen, 29, and did not “appear to begin taking full accountability for the murder until she was finally caught,” the letter says.

Lazarus was convicted of first-degree murder in Rasmussen’s killing in 2009.

Rasmsussen’s sister, Connie, said she was “so very happy” with Monday’s decision.

“It [will] keep her in prison,” she said by text.

A lawyer who represented Lazarus at the November hearing did not immediately respond to a request for comment.

During a parole hearing Monday, several of Lazarus’ supporters described the former art theft detective as a model prisoner who has mentored younger inmates, established a nonprofit that supplies women with textbooks and has taken responsibility for Rasmussen’s murder.

But authorities and the victim’s relatives and friends countered that Lazarus has not appeared remorseful or acknowledged what one of the case’s lead investigators previously described as the “cold, calculated” nature of Rasmussen’s murder.

Opponents also challenged parole officials’ invocation of California’s youthful offender laws in the case. Lazarus was almost 26 at the time of the murder, and legislative reforms in the state have sought to shift how people younger than 26 are handled within the criminal justice system.

At the November hearing, the presiding commissioner said the law should be given “great weight” in helping the panel reach its decision, a transcript of the hearing shows.

Rasmussen’s relatives have questioned why the law was applied to Lazarus, who graduated from the University of California Los Angeles and had been a police officer for two years at the time of the killing. Connie Rasmussen has pointed to the psychological evaluation Lazarus underwent prior to becoming an officer and the fact that she was found fit to carry a gun.

The lead police investigator in the murder, Greg Stearns, said in Monday’s hearing that the sophistication of the crime showed that Lazarus shouldn’t be considered a youthful offender.

On Feb. 24, 1986, a few months after Rasmussen — a nurse — had married a man Lazarus previously dated, the officer entered the couple’s Van Nuys condo and struck Rasmussen in the head with a vase. Lazarus shot the newlywed three times in the chest with a .38 pistol, using a pillow as an improvised silencer, Stearns said.

She then staged the killing to look like a robbery.

Lazarus went on to have a family and work as an art theft detective for the Los Angeles Police Department. She was convicted at trial after asserting her innocence.

During the November hearing, Lazarus said that she had no intention of killing Sherri — she had only planned on talking to her ex — when she went to the couple’s home. She said she didn’t turn herself in afterward because she was ashamed.

Although the commissioner who oversaw the November hearing said she had difficulty with some of Lazarus’ responses during the proceedings — including when the former detective talked about whether she intended to kill Rasmussen when she went to the condo — she said Lazarus had shown remorse and did not pose a risk if released, the transcript shows.

After the victim’s family pleaded with the governor to reverse the parole decision, saying Lazarus had demonstrated a “lack of candor and severe lack of insight” during the November hearing, Newsom asked the state Board of Parole Hearings to weigh in on the matter.

It isn’t clear if a date for the rescission hearing has been set.

This article was originally published on NBCNews.com