Los Angeles authorities are reviewing new evidence that could lead to the release or a new trial of Lyle and Erik Menendez, the Beverly Hills brothers convicted of killing their parents three decades ago, the local district attorney said on Thursday.

The brothers are serving life in prison without parole for the 1989 shotgun murders of their parents. Jose Menendez was shot in the back of the head and Kitty Menendez was shot 15 times. At the time of the murder Lyle was 21 and Erik was 18.

At a televised trial that captivated the United States in 1996, the brothers claimed they had been sexually abused by both parents for years and were acting in self-defense. Prosecutors argued the pair were seeking their parents' multi-million dollar fortune.

Los Angeles District Attorney George Gascon said on Thursday his office would review what he called new evidence that the brothers were molested, including a letter Erik Menendez allegedly wrote eight months before the murders in which he described abuse.

Investigators also are examining allegations from a member of the 1980s pop band Menudo that he was abused by Jose Menendez, who was a music executive. Those allegations were publicized last year in Peacock documentary series called "Menendez + Menudo: Boys Betrayed."

A recent Netflix series, "Monsters: The Lyle and Erik Menendez Story" has revived interest in the case.

The new review could lead to various outcomes, Gascon said. The brothers could be immediately freed or given a new sentence or a fresh trial. Gascon said he had an open mind about the case.

"We’re not ready to believe or do not believe that information," Gascon said at a press conference. "But we're here to tell you that we have a moral and ethical obligation to review what is being presented to us and make a determination."

The Menendez brothers last year petitioned to have their sentence vacated.

On Thursday, their attorney, Mark Geragos, praised Gascon for what he called "a bold step."

"It may not be a popular decision in prosecutorial circles, but I would think that in our culture we’ve come a long way in the last 10 years, maybe 15 years," Geragos told reporters. "I think we’re at a point now where any reasonable person taking a look at this case believes they should be out."