Lyle and Erik Menendez were once maligned as greedy 'crybaby ...

To millions of people in the 1990s, it was the nightmare on Elm Drive.

A wealthy entertainment executive and his wife were shot multiple times at close range while watching television on their couch inside their Beverly Hills mansion on August 20, 1989.

Jose and Kitty Menendez were left almost unrecognisable by the spray of bullets, according to witness reports, and were later said to be discovered by their two young sons, 21-year-old Lyle and 18-year-old Erik.

The brothers claimed they had arrived home from the movies and walked in on the gruesome scene in the living room before calling the police.

"Someone killed my parents," Lyle screamed on the phone to the emergency operator.

When investigators arrived on the tree-lined street in one of Beverly Hills' most prestigious postcodes, they were shocked by the brutality of the crime scene.

"I have heard of very few murders that were more savage," said police chief Marvin Iannone.

The media and the Menendez family were quick to point the finger of blame at the mafia, with the brothers frequently changing hotel rooms after the murder, claiming they feared "the mob" might be after them.

But as months ticked by with no arrests, the strange behaviour of Lyle and Eric in the aftermath of the slaying of their parents attracted the attention of authorities.

They were arrested on March 8, 1990 and charged with the murder of Jose and Kitty Menendez.

The brothers soon admitted to the killings, but insisted they acted in self-defence after years of sexual, emotional, and physical abuse, something prosecutor David Conn ridiculed as "the silliest, most ridiculous story ever told in a courtroom".

After two high-profile trials, one that ended in a deadlocked jury, Lyle and Erik were sentenced to life behind bars.

For almost 30 years, they have carried out their terms behind bars in separate Californian jail cells.

But in the intervening decades, a movement against sexual abuse and the systems of power that enable it has spread around the world, debunking toxic social assumptions of the crime and educating generations of people on how to recognise and prosecute the behaviour.

A Netflix series about the case, Monsters, also reignited interest in the Menendez brothers.

Now they have a chance at freedom.

This week, Los Angeles County district attorney, George Gascón, recommended that Lyle and Erik Menendez be re-sentenced, which could ultimately lead to their release.

Los Angeles County District Attorney George Gascon shakes hands with relatives of the Menendez brothers after he recommended they should be resentenced.  (Reuters: Mike Blake)

"I believe that they have paid their debt to society," Mr Gascón said.

Here is how these two brothers went from being the arch-villains of America's burgeoning true crime obsession, to becoming the focus of an impassioned movement to free them.

The shocking crime that gripped 90s America

The horror found inside the Menendez mansion in 1989 came to symbolise the death of the American Dream.

Here was a couple that seemed to have it all — money, power, stability, and two perfect sons.

So when those young men were accused of charging into the mansion with a pair of 12-gauge shotguns to gain early access to their inheritance, the case seemed to speak to the excess, violence, and dissolution of the family unit of the era.

The brothers were described by police as acting remarkably calm on the night of the murder before embarking on a $US700,000 ($1 million) spending spree with their $US15 million inheritance.

Erik Menendez, left, and his brother Lyle, were arrested six months after their parents died.  (Los Angeles Times via Getty Images: Larry Davis)

A Porsche, new clothes, a $15,000 Rolex watch and professional tennis lessons were among the list of extravagant purchases made by the pair.

Physical evidence was scarce, until the mistress of the psychologist treating one of the brothers, Judolyn Smyth, tipped off police that the men had confessed to killing their parents on an audiotape of a counselling session.

The case gripped the nation, with journalists reporting in vivid detail the twists and turns of the investigation into the two brothers and the trial that followed.

But what might have been lost in the public's obsession with the gruesome crime in a privileged neighbourhood was what drove two men to commit murder against their own family.

Lyle and Erik claimed they had experienced unimaginable abuse at the hands of their father, which drove them to kill him.

"I just told him that I didn't want to do this and that it hurt me. And he said he didn't mean to hurt me and he loved me," Lyle testified at his trial in 1993.

Lyle said his mother was well aware of the alleged abuse, and blamed her son for it.

Erik Menendez (right) and his brother Lyle told the court that their father subjected them both to sexual abuse.  (Reuters: Lee Celano)

"I told her to tell dad to leave me alone, that he keeps touching me," Lyle said.

"She told me to stop it and that I was exaggerating — and that my dad has to punish me when I do things wrong. She told me he loved me."

Lyle said he murdered his parents three days after learning his younger brother Erik had also been subjected to sexual abuse at the the hands of his father.

"Did you kill them for money?" their defence attorney Jill Lansing asked.

"No," Lyle responded.

"Why did you kill your parents?" she asked.

"Because we were afraid," he said.

A lasting verdict

After the first trial ended in a deadlock, the brothers were brought before the courts again in 1995.

Their allegations of abuse were poorly understood by the public and the court system at the time.

They were the objects of ridicule on late night comedy shows, including a much-maligned skit broadcast on Saturday Night Live in 1993.

Brothers Erik (L) and Lyle Menendez were convicted on March 20, 1996 of the first degree murder of their wealthy Beverly Hills parents. (Reuters: HO SN)

The prosecution argued Lyle and Erik were motivated purely by greed.

"Lyle Menendez did not have the drive. He did not have the intellect. He did not have the motivation," David Conn told the jury.

"And Erik Menendez was an even greater failure. He was weak. Erik Menendez was soft… He was described as a crybaby."

Prosecutors argued Erik and his brother Lyle killed their parents for the inheritance. (Reuters)

Judge Stanley Weisberg limited testimony on what was dubbed the "abuse excuse" defence, and later ruled the argument couldn't be used at all.

A jury of 12 ultimately found the pair guilty.

But the verdict didn't end the public's fascination with the case, or stop people from speculating about what went wrong inside the Menendez living room that day.

Why shifting attitudes shone a new light on the brothers

Decades later, a global reckoning over sexual abuse committed by people in positions of power and the insidious ways it was covered up has sparked several criminal proceedings.

"I think people have a more nuanced take now on what it means to be a victim of that kind of abuse," Oakland-based attorney Hanni Fakhoury told Bloomberg.

"People are more willing to speak out on it, and the courts are trying to do something more about it."

At the same time, there has been growing momentum to re-evaluate cases with large sentences in the wake of the First Step Act, signed in 2018.

Along with shifting perceptions, the Menendez case has benefited from more scrutiny due to recent docuseries and new evidence.

Last year, Roy Rosselló, a former member of 1980s boy band Menudo, came forward with an allegation that he was sexually assaulted as a 14-year-old by Jose Menendez.

Menendez was working as an executive at RCA Records when his company signed Menudo to a recording contract.

In his account of the abuse, Mr Rossello said he went to the Menendez mansion and lost control of his body after drinking one glass of wine. He said he was then raped.

"I know what he did to me in his house," Mr Rosselló said in Menendez + Menudo: Boys Betrayed.

The Menendez brothers' attorney, Cliff Gardner, filed a petition last year citing Rossello's account and other new evidence that proved the brothers' claims they were sexually abused by their father.

The petition is separate to the recent announcement of a re-examination of the brothers' sentencing.

That has largely been driven by a newly discovered piece of evidence.

In a letter written by Erik to his cousin Andy Cano in 1988, months before the murders, the Menendez boy revealed he was trying to avoid his dad.

New evidence includes a letter Erik wrote to his cousin before the murders took place. (Reuters: STR New)

The correspondence was never presented in the trials and was only discovered in storage by Cano's mother, years after his death in 2003.

"It's still happening, Andy, but it's worse for me now … Every night I stay up thinking he might come in. I need to put it out of my mind," the letter reads.

"…He's crazy. He's warned me a hundred times about telling anyone, especially Lyle."

Cano testified at the Menendez brothers' first trial, but his statement that a 13-year-old Erik Menendez had told him that his father was touching him inappropriately was rejected by prosecutors, who suggested that Cano was lying.

What now for Lyle and Erik?

Thirty years later, the brothers' lengthy jail terms are set to be re-examined in light of recent evidence.

On Thursday, local time, Los Angeles district attorney George Gascón announced he would recommend a resentencing that would make the brothers eligible for immediate parole.

He hinted at a few reasons for the decision, including the brothers' work to improve the lives of their fellow inmates and recent documentaries, including one on Netflix.

"I believe the brothers were subject to a tremendous amount of dysfunction in their home and molestation," he said, adding there is no excuse for murder.

The final decision on whether to resentence the brothers will be up to a judge, with a hearing likely to take place in 30 to 45 days from now.

If granted, the brothers could be immediately eligible to appear before a parole board.

The news of Lyle and Erik's possible release has been welcomed by their friends and family, who issued a plea earlier this month for the two men to be freed.

"The world was not ready to believe that boys could be raped or that young men could be victims of sexual violence," Joan Andersen VanderMolen, sister of Kitty Menendez, said at a press conference.

"Today we know better. We know that abuse has long-lasting effects and victims of trauma sometimes act in ways that are very difficult to understand."

Joan Andersen VanderMolen, sister of Kitty Menendez, joined the family's pleas earlier this month. (Reuters: Mike Blake)

But there are others who want the brothers to remain behind bars.

"Mr Andersen firmly believes that his nephews were not molested," Kathy Cady, an attorney representing Milton Andersen, the brother of Kitty Menendez, told US media.

"He believes that is a fabrication and he believes that the motive was pure greed."

Whatever happens next, the latest twist in the Menendez case has reinforced how changing social attitudes are impacting the legal system and highlight the enduring legacy of the case three decades on.

"I think it was easy for people in the beginning to think these two spoiled rich kids will kill their parents for the money, for the inheritance, but it's much more complicated," said Nathan Lane, who played late Vanity Fair reporter Dominick Dunne, who extensively covered the murders.

"It doesn't change the fact that they committed this horrific act, but I think maybe you start to understand what led to that."