Ryan Murphy, the creator of Netflix’s Monsters: The Lyle and Erik Menendez Story, has called their family’s negative response to the drama, about two brothers who killed their parents, “predictable at best”.

Members of the Menendez brothers’ family say the pair have been “victimised by this grotesque shockadrama,” adding the show is “riddled with mistruths”.

Murphy told Variety their response was “interesting because I would like specifics about what they think is shocking or not shocking. It’s not like we’re making any of this stuff up. It’s all been presented before”.

He added that the family “don’t say what the lies are, they don’t back up anything”, and that his drama is the first to present the story “in one contained ecosystem”.

The family’s statement also said: “The character assassination of Erik and Lyle, who are our nephews and cousins, under the guise of a ‘story telling narrative’, is repulsive.”

They added: “We love them and to this very day we are close to them. We also know what went on in their home and the unimaginably turbulent lives they have endured.

“Several of us were eyewitnesses to many atrocities one should never have to bear witness to.”

The brothers, ages 18 and 21 at the time of the 1989 killings, shot their wealthy parents Jose and Kitty Menendez at point-blank range in their Beverly Hills mansion.

Prosecutors argued during the high-profile trial that the the young men had killed their successful parents to inherit their multi-million-dollar estate. But the brothers’ defence lawyers said it was revenge for sexual abuse, although no molestation was ever proven in court.

The trial began in 1993, resulting in two deadlocked juries in 1994, before the case was retried in 1995, when the judge excluded evidence of abuse from their defence case.

A jury found them guilty and the pair were convicted of first-degree murder and conspiracy to murder in 1996, and they were sentenced to life imprisonment without the possibility of parole.

The brothers reunited in jail in 2018.

The show stars Cooper Koch and Nicholas Alexander Chavez as the brothers, and Javier Bardem and Chloe Sevigny as their parents.

Murphy is also the director, writer and producer behind series including Glee, Pose, The Watcher, Feud, American Horror Story, Hollywood and Ratched, and he created Monsters with Ian Brennan, who co-created Glee.

The series was reported to have had 12.3 million views in its first weekend of release, although it is not known how many individual viewers or households that amounts to, as it is split across the nine episodes.

Murphy thinks the series is “the best thing that has happened to the Menendez brothers in 30 years”, Variety reported.

“They are now being talked about by millions of people all over the world. There’s a documentary coming out in two weeks about them, also on Netflix.”

He added it is “asking really difficult questions”, such as should they get a new trial, should they be released, whether people should be locked up for life and “is there no chance ever at rehabilitation?”.

“It’s giving these brothers another trial in the court of public opinion. From what I can tell, it’s really opened up the possibility that this evidence that they claim that they have, maybe that there is going to be a way forward for them.”

The producer added he believes that if the trial were held today, the brothers may have received a lesser charge of manslaughter and a lighter sentence.

Cooper Koch, who plays Erik, told Variety on Thursday he spoke to him for the first time the night before Netflix released the series.

The actor also said he met both brothers about a week later, joining Kim Kardashian in a visit to inmates, to discuss prison reform.

Kardashian already visits prisons to explore information about rehabilitation programmes, which she shares on her programmes.

But Murphy told Variety he has “no interest” in talking to the brothers, although he thinks it’s “very good” that Koch has a relationship with them, and he believes Kardashian “does God’s work”.

“I believe in everything she believes in. I don’t know what I would say to them. What would I ask them? I know what their perspective is,” he added.