The Sandy Hook Elementary School mass killer revealed the extent of his obsession with a chimpanzee that savaged a woman, in a call to a programme called Anarchy Radio.
Killer Adam Lanza made the call to the programme on an Oregon college radio station in December 2011 – a year before his murder spree at Sandy Hook, the New York Daily News reported.
Calling himself Greg and disguising his voice, Lanza's call lasted more than seven minutes.
During it he compared a "teenage mall shooter" to the chimpanzee called Travis, which mauled its owner's friend, Charla Nash, in February 2009, in the US.
The 14-year-old chimp ripped off Nash's nose, hands, lips and eyelids before being shot dead by a police officer.
Nash, who had a face transplant, is blind, has no hands and lives in a nursing home.
"His attack can be seen entirely parallel to the attacks and random acts of violence that you bring up on your show every week, committed by humans, which the mainstream also has no explanation," Lanza said of Travis.
"I just ... don't think it would be such a stretch to say that he very well could have been a teenage mall shooter or something like that."
Lanza said Travis' lashing out "wasn't simply because he was a senselessly violent, impulsive chimp".
"Travis wasn't an untamed monster at all.
"He wasn't just feigning domestication, he was civilised ... he was able to integrate into society.
"His owner drove him around the city frequently in association with her towing business, where he met many different people, and got along with everyone."
Lanza told the radio programme: "It seems like everyone who knew him said how shocked they were that Travis had been so savage, because they knew him as a sweet child."
Nash had tried to coax Travis back into his place of domestication, and the chimp could not handle it.
"So he attacked her, and anyone else who approached them," Lanza said. "And dismissing his attack as simply being the senseless violence and impulsiveness of a chimp, instead of a human, is wishful thinking at best."
Lanza (aka Greg) said that what happened with Travis "brings up questions about this whole process of child-raising".
"Civilisation isn't something which just happens to gently exist without us having to do anything, because every newborn child - human child - is born in a chimp-like state, and civilisation is only sustained by conditioning them for years on end."
Anarchy Radio host John Zerzan, a guru of the anarcho-primitivist movement that regards technology as a destroyer of society, told the NY Daily News that what Lanza said on the programme made sense.
"There's nothing there indicating he was considering something so heinous and inconceivable. It was a year before Sandy Hook, so no-one has any idea what he was thinking a year before ... I don't see how anyone could have guessed that with what was said."
Starting in December 2009, Lanza also began posting as Smiggles to Shocked Beyond Belief, a fan website for a video game based on the 1999 massacre of 12 students and a teacher at Columbine High School.
Among other things, Smiggles praised Norwegian mass murderer Anders Breivik in an August 2011 post for killing more people than Woo Bum-kon, the South Korean police officer who killed 56 people and wounded 35 more before killing himself in 1982, the NY Daily News said.
In January 2011, Lanza posted: "I castrated myself when I was 15 to rebel against society."
In August 2011 he said: "A degenerate capitalistic system results in a commodification of sexuality.
"This enables the creation of a cultural notion that premarital sexuality is acceptable," he wrote. "This results in sexuality becoming widespread."
In September 2011 "Smiggles" said: "I used to think I was asexual, but the primary reason why I thought that was because my BMI (body mass index) was 14."
Lanza was extremely thin.
In December 2012, 20-year-old Lanza fatally shot 20 children and six adult staff members in a mass murder at the Sandy Hook school.
Before driving to the school, he shot and killed his mother, Nancy.
He committed suicide by shooting himself in the head as emergency services arrived at the school.
- Fairfax Media