• In “Born Evil,” convicted murderer Hadden Clark opens up to director Michael Bay from prison in a series of recorded, disturbing phone conversations

• Convicted murderer Jack Truitt, who Clark believed was Jesus, describes in detail how Clark confessed his sins to him – including a bombshell that led authorities to solve a long-held mystery

• Bay believes some of Clark’s claims in the documentary “could potentially open the door to solving many unsolved murder cases”

The handwritten letter from the Eastern Correctional Institution in Westover, Maryland, remained unopened for two weeks.

“It was in another room, not where I go,” director Michael Bay tells PEOPLE. “It just sat there. I didn’t want that dark energy around me.”

As a director of action-packed big-budget blockbusters, including Armageddon, the first five Transformers Films and the Bad Boys Bay says he likes to “explore and develop characters” by talking to people in the real world, from alligator trappers to NASA physicists and astronauts.

But he has never spoken to a serial killer, let alone one who admitted to eating the flesh of 6-year-old Michelle Dorr, whom he murdered in Silver Spring, Maryland, in 1986, or who admitted to stabbing 23-year-old Laura Hoeteling to death in her Bethesda home in 1992 while, he claims, wearing a wig and women’s clothing.

So Bay was curious to see what convicted murderer Hadden Clark had written to him in April 2023, a month after Bay sent the killer a letter in prison asking if he would be willing to talk to him.

Clark was interested.

“I wanted to understand his psyche,” says Bay. “The twisted mind of a serial killer.”

Bay’s subsequent prison conversations with the former trained chef – and the explosive confessions Clark allegedly made to Jack Truitt, the long-haired, bearded cellmate he believed to be Jesus – became the basis for Bay’s latest project. Born Evil: The Serial Killer and the Savioron Investigation Discovery/ID and streaming on Max. (An exclusive clip is shown below.)

The five-part docuseries – Bay’s first documentary and his first project with the True Crime Network – begins Monday, Sept. 2 at 9/8c and takes an in-depth look at the grisly murders for which Clark served 60 years in prison, not to mention the countless other people the now 72-year-old, diagnosed with paranoid schizophrenia, claims to have killed.

In more than 14 hours of private, recorded conversations from prison, Bay, the series’ executive producer, spoke to a criminal “who the FBI has designated as a ‘person of interest’ in more than 20 states,” Bay says.

Evil from birth he says in an ID press release, “could potentially open the door to solving many unsolved murder cases.”

But first he shows what drives Clark.

In insightful, often terrifying conversations, Bay gets Clark to talk about his life, starting with his broken childhood and how it shaped him.

“The Clarks are similar to the Beaver Cleaver family,” says Bay. “But Hadden said he was really psychologically abused.”

Growing up, Clark says, he was often called derogatory names by his parents – and other children. His alcoholic mother, he says, forced him to wear dresses and called him “Kristen.”

“His upbringing was very sad,” says Bay.

Murder runs in the family

Bay learned about Clark through one of his longtime collaborators, Corey Turner, and filmmaker Paul Hogan, who are executive producers on the project. Hogan told Bay he remembered seeing Clark when he was 13, when Clark worked as a gardener and lived in a small white truck at Hogan’s church in Bethesda. “Something seemed off about him,” Hogan says.

Bay was fascinated and began to look into it more closely. “As a director, I’m always looking for a hook, for something different, and I delved deeper and deeper into the subject matter,” he says.

In this case, he says, “the hook was a family of serial killers you’ve never heard of.”

Clark’s brother, Bradfield Clark, now 73, was convicted in 1985 of murdering and dismembering a colleague in California, allegedly eating parts of her body.

Clark claims he learned to kill when he witnessed his late father murder a woman. Clark, in turn, claims to have killed countless others. Viewers become aware of this when Clark’s cellmate Jack Truitt, a convicted murderer, forces Clark – who believes Truitt is Jesus – to reveal an important, long-held and deadly secret.

Cold Case “Treasure Chest?”

Bay says he was gentle with Clark at first.

“And then there were times when I started to challenge him a little bit more and be tougher on him,” he says. “I would say, ‘So what do you mean you felt bad?’ There was a long pause and then he would say, ‘Yeah, because of the bad things I did. But I’m a good person at heart.'”

The documentary features macabre drawings by Clark, including one that reads: “I trick them and then I eat them.”

“He has quotes that are absolutely dark,” says Bay. “It’s like looking for the most disgusting lines in a movie – this guy writes those lines.”

One of the most irritating moments in the documentary is when Clark throws around a series of female names, prompting Bay to ask in a recorded conversation, “Hadden, wait, who are all these women?”

The names could provide investigators with potential clues to solve other suspected murders.

“This show can bring all these other cases to light,” he says. “So it’s like a treasure chest.”

“The best thing we can do is help families find closure and peace,” he says.

Born Evil: The Serial Killer and the Saviorwill premiere on ID on three evenings starting Monday, September 2nd, at 9/8c.