THE parents of Elliot Rodger had been desperately trying to stop their son carrying out his killing spree when they heard about the massacre in Isla Vista, California, on the radio, it emerged on Sunday.

Just minutes before the 22-year-old went on a knife and gun rampage in the student beach community on Friday, he emailed a 137-page manifesto detailing his plans to some 30 people including his mother, father and former teachers.

In that document Rodger, the son of Hollywood director Peter Rodger, details how he plans to first kill his housemates, then lure others to his residence to continue the violence before slaughtering women in a sorority and continuing his spree near the University of California Santa Barbara (UCSB).

Family friend Simon Astaire told Reuters that Rodger's mother, Chin Rodger, received a phone call on the night of the shooting from his therapist alerting her to the manifesto.

She called police and her ex-husband and the two parents raced to Isla Vista, he said. But it was too late - Ms Rodger heard radio reports about the shootings as she drove and police in Santa Barbara told the pair their son was believed to be the gunman.

Rodger, who was born in London and moved to the US aged five, stabbed his three flatmates to death before shooting dead two young women outside a sorority house and then killing a young man inside the IV Deli Mart.

He then drove around the streets in his black BMW, randomly shooting at pedestrians. After getting into a gun battle with deputies, he turned the weapon on himself.

Elliot Rodger on Facebook
Elliot Rodger on Facebook

All six victims of the mass killing have been named by police: the three men stabbed to death were identified as 19-year-old George Chen and Cheng Yuan Hong and Weihan Wang, both 20; and the three people shot were named as 22-year-old Katie Cooper, 19-year-old Veronkia Weiss and 20-year-old Christopher Michael-Martinez.

Mr Astaire said that Rodger had seen therapists off and on since he was nine years old and was reserved to the point of seeming to have trouble communicating with "an underlying sadness about him, a frustration".

But he added: "There was no suggestion that he had any interest, any liking for guns."

In a video uploaded to YouTube the day before the massacre, entitled "Elliot Rodger's Retribution", the suspect chillingly foretells the killings.

He describes his plans to shoot women and promises retribution for his "loneliness and frustration" at never having had a girlfriend and for being a virgin.

Cathleen Bloeser, 58, whose son was a childhood friend of the shooter and was included on the email chain, said it had become clear that Rodger's behaviour was a source of concern in the lead-up to the tragedy.

"We could see that he was turning," she said, adding that Rodger talked to her 22-year-old son and another friend about sexual crimes he wanted to commit against women.

She said Rodger had talked to her son about wanting to hold down and rape women. Within the last year, his mental health deteriorated and he was under psychiatric care but not taking his medication.

"He'd changed emotionally and he'd become very despondent and he wanted to get back at people," she said.

More on this story at The Independent