The family of convicted murderers Erik and Lyle Menendez are demanding their release from prison, 35 years after their parents were murdered in their Beverly Hills home.

The brothers were convicted of the 1989 murders of Jose and Kitty Menendez and sentenced to life in prison without the possibility of parole. But family members argue that the boys had been sexually abused by their father in the past, and the judge overseeing the case never let the defense present much of that evidence to the jury.

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At a news conference Wednesday in downtown Los Angeles, more than a dozen relatives of the Menendez brothers spoke along with their attorney Mark Geragos, calling on Los Angeles County District Attorney George Gascón to re-sentence the brothers based on new evidence to reflect on – including a letter from Erik Menendez in which he alludes to abuse he suffered before the murders.

“I had no idea the extent of the abuse they had suffered at the hands of my brother-in-law. None of us knew,” said Joan Andersen VanderMolen, Kitty Menendez’s sister. “We know that abuse has long-term effects and victims of trauma sometimes act in ways that are very difficult to understand.”

Wednesday’s news conference comes less than two weeks after Gascón’s office announced it would review the new evidence to decide again whether the Menendez brothers should serve life sentences. If a retrial or resentencing is granted, it is possible that the Menendez brothers, now in their 50s, could be released based on time served.

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Lyle and Erik, who were 21 and 18 at the time of the murders, claim they killed their parents after years of sexual assault. However, prosecutors argued that they were motivated by financial reasons since Jose Menendez was a wealthy record company executive.

According to the California Department of Corrections, both Menendez brothers remain incarcerated at California’s RJ Donovan Correctional Facility. In the decades since her arrest, her case has continued to captivate the true crime world – most recently with a Netflix series called “Monsters: The Lyle and Erik Menendez Story,” which premiered last month.