The LA District Attorney's Office will announce its decision to resentence the Menendez brothers on Thursday

Los Angeles County District Attorney George Gascón said he will announce his decision Thursday regarding the possible resentencing of Lyle and Erik Menendez, who are each serving two consecutive life sentences without parole.

Gascón will hold a press conference at 1:30 p.m. local time.

Watch “Menendez Brothers: Monsters or Victims?” from “IMPACT by Nightline,” streaming now only on Hulu. (Disney is the parent company of Hulu and ABC News).

If Gascón recommends a resentencing due to pressure from relatives, lawyers and the brothers' public supporters, his decision will be presented to a judge who will decide whether Lyle and Erik Menendez should be released from prison and given a more lenient sentence or receive one new trial version.

Gascón told ABC News this month that any resentencing recommendation would take into account the decades the brothers have already served and their behavior in prison. The brothers' attorney, Mark Geragos, called them model prisoners who worked tirelessly to reform themselves without expecting to be released.

The decades-old case began on August 20, 1989, when Lyle and Erik Menendez fatally shot their parents Jose and Kitty Menendez in the family's Beverly Hills home. Lyle Menendez, then 21, and Erik Menendez, then 18, were using shotguns they had purchased days earlier.

Prosecutors alleged the brothers killed their wealthy parents for financial gain.

The defense argued the brothers acted in self-defense after enduring years of sexual abuse at the hands of their father.

Their first trials — which captured the nation's attention with courtroom cameras — ended in mistrials.

In 1996, at the end of a second trial – in which the judge rejected much of the sexual abuse evidence – the brothers were convicted of first-degree murder and sentenced to two consecutive life sentences without the possibility of parole.

The high-profile case gained new attention in the fall with the release of the Netflix drama “Monsters: The Lyle and Erik Menendez Story” and the Netflix documentary “The Menendez Brothers.”

Gascón said this month that his office was examining new evidence: allegations from a member of the boy band Menudo who said he was molested by Jose Menendez, and a letter Erik Menendez wrote to a cousin eight months before the murders in which he gave his alleged ill-treatment in detail.

Erik Menendez's cousin testified in court about the alleged abuse, but Erik Menendez's letter – which would have corroborated the cousin's testimony – was only unearthed several years ago, according to Geragos.

Nearly two dozen of the brothers' relatives gathered at a news conference last week to urge resentencing.

“While their actions were tragic, they were the desperate response of two boys trying to survive their father's unspeakable cruelty,” said Kitty Menendez's sister, Joan Andersen VanderMolen. “As their aunt, I had no idea of ​​the extent of the abuse they suffered.”

“It is time to give them the opportunity to live the rest of their lives free from the shadow of their past,” she said.

Behind bars, the siblings tried to “better themselves and serve as support and inspiration to survivors around the world,” added Jose Menendez's niece, Anamaria Baralt. “Their continued detention serves no purpose of rehabilitation.”

The brothers “deserve a chance to heal, and our family deserves a chance to heal with them,” Baralt said.

Despite the outpouring of support, one relative – the brothers' uncle, Milton Andersen – is adamant about keeping them behind bars. He said in a statement that he firmly believes his nephews were not sexually abused and were motivated by greed.

This is a developing story. Please check back for updates.