Movie that 'inspired Menendez brothers to kill their parents' immediately after watching it

During the trial of Lyle and Erik Menendez, who were sentenced to life in prison without the possibility of parole, one of the witnesses claimed they were inspired by a 1987 movie.

The Menendez brothers are the subject of new Netflix drama Monsters: The Lyle and Erik Menendez Story, which follows the true crime tale of them murdering their parents.

According to the Los Angeles Times back when the trial was on, the chief witness for the prosecution caused confusion in the courtroom when they said that Lyle and Erik Menendez got the idea to murder their parents 'on the BBC'.

At first, people had assumed they'd meant the BBC as in the British Broadcasting Corporation, but they'd actually meant the 1987 film Billionaire Boys Club.

Psychologist L. Jerome Oziel was therapist to both of the Menendez brothers and claimed that Erik confessed to him during a session, which he then told to his mistress who then told the police after they broke off the affair.

The 1987 movie Billionaire Boy's Club was named during the Menendez brothers trial as an inspiration. (NBC)

The LA Times reported that Oziel pointed towards the movie, while Deputy District Attorney Lester Kuriyama said 'sent chills up my spine' and tried to persuade the court to allow the film to be played to the jury.

However, this request was rebuffed as the judge asked the prosecutor whether he was 'going to sell popcorn', and the trial continued.

As for the movie itself, Billionaire Boys Club follows the story of a group of men on trial in Los Angeles after setting up a Ponzi scheme to make money and killing people to get them out of the way.

This is the film the therapist claimed inspired Lyle and Erik Menendez, who in 1989 murdered their parents, José and Kitty.

They then called the police to claim they'd come home from watching Batman at the cinema and discovered the bodies.

Lyle and Erik Menendez claimed they'd been abused by their parents. (MIKE NELSON/AFP via Getty Images)

At the trial, the defence didn't dispute that the brothers had murdered their parents, but claimed that it was an act of self-defence after years of abuse.

Prosecutors argued that they'd murdered their parents to get their hands on the inheritance money, while Lyle and Erik provided the court with graphic descriptions of abuse they claimed they suffered at their father's hands.

In the end, they were sentenced to life in prison without the possibility of parole, but did not receive the death penalty.

The brothers were sent to separate maximum security prisons for 22 years, but were reunited in 2018 when Lyle was moved to the Richard J. Donovan Correctional Facility in San Diego where Erik had been sent.

Monsters: The Lyle and Erik Menendez Story is available on Netflix now.