Harrowing audio of Menendez brother telling police his parents are dead after he and his sibling killed them

The second season of Netflix's Monster true crime series has been released today (19 September) and it follows the harrowing story of Lyle and Erik Menendez.

Monsters: The Lyle and Erik Menendez Story aims to tell the tale of the brothers who murdered their parents one night in August 1989.

Initially the brothers claimed they'd been out to the cinema and returned to find the bodies of their parents Jose, 45, and Kitty, 47, having been shot dead in their Beverly Hills home.

The call they placed to the police in the immediate aftermath of the killing has them acting hysterically as Lyle wails 'someone killed my parents' while Erik can be heard yelling in the background.

In the call made to the police, Lyle said he didn't think the person who committed the murders was still there as he spoke to two dispatchers who tried to work out what was happening.

The brothers murdered their parents and then called the police. (YouTube/Menendez Case)

At one point Lyle was heard shouting 'Erik, get away from them' but didn't put his brother on, claiming he was 'hysterical'.

Police initially considered the idea that it might be some kind of mob-related attack, but suspicion eventually turned back on the Menendez brothers.

In the aftermath of the murders they embarked on lavish spending sprees, resulting in the finger of suspicion being pointed towards them.

Cops fitted one of Erik's friends with a wire to try and get him to confess, but he denied murdering his parents.

However, Erik later confessed during a therapy session, his therapist then spilled the beans to his mistress and when their secret relationship broke up she went and told the police.

In a recording Erik said they'd killed their mother to put her 'out of her misery' and that they believed their father deserved to die because he'd been unfaithful and caused her despair.

Despite the dramatic 911 call suspicion eventually fell on Lyle and Erik Menendez, who ended up being convicted of the murders. (MIKE NELSON/AFP via Getty Images)

They had shot their mother and father multiple times with shotguns, Lyle had even returned to their car to reload his gun.

Afterwards, the brothers had stashed their weapons and made sure they had tickets to Batman to back up their story that they were out at the movies.

During their trial the Menendez brothers claimed their father had molested them throughout their childhoods, giving graphic descriptions of what they claimed he'd done to them.

Two of their cousins also testified to support Lyle and Erik's claims, but prosecutors argued that they'd said none of this to their therapist.

Judalyon Smyth, the woman who first told the police about the confession to the therapist, would later claim she'd been 'brainwashed' into saying she overheard the confession herself.

In the end both brothers were sentenced to life in prison without the possibility of parole.

Monsters: The Lyle and Erik Menendez Story is available to watch now on Netflix, a third season starring Charlie Hunnam has already been commissioned and will focus on the story of serial killer Ed Gein.