Serial killer Charles Manson confessed to multiple murders in a newly released prison phone call, but a forensic psychologist told Fox News Digital that his claims should be met with a degree of skepticism.

“There’s a whole part of my life that nobody knows about,” Manson said in the phone call, featured in a short teaser clip for Peacock’s upcoming documentary series “Making Manson.”

“I lived in Mexico for a while. I went to Acapulco, stole some cars,” continued Manson, who died at age 83 in November 2017. “I just got into things over the top, man. I involved in a few murders. I left my .357 Magnum in Mexico City and left some dead on the beach.”

HIPPIE CULT LEADER CHARLES MANSON DIED AT 83

Charles Manson was convicted of one count of murder and several counts of attempted murder. He was the leader of the Manson Family, a cult that committed several murders at Manson’s behest. (AP/Ron Galella)

The documentary, which premieres Tuesday, delves into more than two decades of previously unreleased conversations with the infamous cult figure, offering a deeper look at his childhood and life of crime before forming “The Manson Family” and during his time as a cult leader

FOLLOW THE FOX TRUE CRIME TEAM ON X

The documentary also features interviews with his family members and people who knew him personally, as well as his continued violent behavior behind bars, where he assaulted several guards, started fires in his cell, and caused general mayhem.

“Charlie was very good at being bad and not showing it,” Phil Kaufman, Manson’s former cellmate, says on the show. “Anything that distracted him from his game plan at that point would crush him, but he did it with velvet gloves.”

Manson killer LESLIE VAN HOUTEN to be paroled after NEWSOM withdraws challenge

A photo of Charles Manson from August 14, 2017, a month before he died of natural causes behind bars at age 83. (California Department of Corrections and Rehabilitation presents Charles Manson)

Manson spent more than 45 years in prison after being convicted of directing his “Manson Family” — a troubled clan of mostly female followers he amassed using charisma and hallucinogenic drugs — to kill the at least seven people in California in the summer of 1969. Among the dead was director Roman Polanski’s pregnant wife, Sharon Tate, who was stabbed 16 times.

Manson didn’t directly commit the murders — instead, he used psychological manipulation to incite his followers to kill as part of his “Helter Skelter” plot, which he believed would start a race war.

SIGN UP FOR THE TRUE CRIME NEWSLETTER

Forensic psychologist Kris Mohandie told Fox News Digital that he wouldn’t be surprised if Manson had committed crimes in addition to the ones he was convicted of — but that, on the contrary, his claims cannot be trusted.

“It’s not surprising at all,” Mohandie said. “He was a psychopath, and you know, really engaged in a lot of different criminal behavior and violence, and he convinced his followers to do violence. It wouldn’t surprise me at all given his history and what we know of what a psychopath he was. .

“He’s very comfortable manipulating people, hurting people, dominating people and taking advantage of people … it wouldn’t surprise me if there are other crimes that he’s historically responsible for.”

DANNY MASTERSON MOVED FROM ‘CHARLES MANSON’ PRISON TO MEDIUM SECURITY CENTRAL FACILITY AFTER INCORPORATION FOR ‘WELFARE’

Seven deputies escort Charles Manson from the courtroom after he and three followers were found guilty of seven counts in the Tate-LaBianca murders. (Bettmann/Getty Images)

“Most people who have been found responsible for multiple crimes, like serial killers and such, (everyone says), ‘This person killed so many people,’ but you only know what they were caught for,” a he continued.

CLICK HERE TO GET THE FOX NEWS APP

However, Mohandie argued, Manson was a “liar and an attention seeker”.

“A person like him also lies and is extremely manipulative. The truth of what he really was will never be known,” Mohandie said. “A psychopath like him lies if there’s anything to be gained for it, for things as simple as attention or shocking people — that becomes a complicated variable to ever get to the truth. We’ll never know what it was – people like him, and especially him, lie, cheat and manipulate for all sorts of motivations.”

Criminology expert James Pipe said the new revelations were “a stark reminder of the long-lasting consequences of Manson’s actions and the importance of remaining vigilant in our pursuit of the truth, no matter how much time has passed.”

GET REAL TIME UPDATES DIRECT ON TRUE CRIME HUB

“Manson’s admission to additional crimes fundamentally changes what we thought we knew about his criminal history,” Pipe told Fox News Digital. “If proven, these allegations point to a broader pattern of violence that extends beyond his notorious crimes in the United States. Law enforcement must thoroughly investigate these claims, particularly in relation to the unsolved cases in Mexico, to ensure that every possible victim receives justice. .”