Following his arrest in July 2023, suspect Rex Heuermann, thought to be the Gilgo Beach serial killer, has been closely watched. Yet, the 61-year-old architect from Long Island continues to be an enigma.

Peacock’s revealing documentary, The Gilgo Beach Killer: House of Secrets, now available for streaming, provides perspectives from the alleged killer’s estranged wife and adult children, along with insights from an unexpected insider.

“I’m caught in a narrative I never wanted,” states David Jimenez, who had known Heuermann for 17 years prior to the arrest, in the documentary. “I’m the best friend of a serial killer. The chances of that happening are one in 250 million. It’s like I’ve won the lottery, but without any prize money—not the kind of lottery you want to win.”

Jimenez, who is also an architect, said that Heuermann could be “really nice” but could turn in a flash. He said he found that out when he came face to face with “the monster that’s hiding in there.”

Heuermann has been charged with killing seven women whose remains were found along the southern shore of Long Island, near the water. He’s pleaded not guilty to all charges. 

David Jimenez meets “the monster” in Rex Heuermann

Jimenez told the documentary’s producers that Heuermann “was easy to be friends with. We’d go to the range and shoot rifles, pistols, all kinds of guns.”

But Jimenez recalled that during one of these outings, he had a stark awakening when he “made the mistake of touching the gun when Rex was down range picking up targets.” 

Jimenez demonstrated for cameras the sound that Heuermann heard when he handled the gun. 

Heuermann’s reaction to the movement shocked Jimenez. “He pulled out his gun,” Jimenez shared. “He started running to me, ‘What the f–k are you doing? What are you doing?” 

Jimenez described how Heuermann got in his face and pointed a gun right at him. “He got this close to me like this,” Jimenez  said. “And I put up my hands and said, ‘I’m sorry, I’m sorry, I’m sorry, Rex… Rex, put the gun down.”

Of the incident, Jimenez said, “It was really scary. Thinking back now, I think that was the monster that’s hiding in there.”

“I think he did it,” Rex Heuermann’s friend says

Since his arrest, Heuermann has been behind bars at the Riverhead Correctional Facility in Suffolk County, New York, where Jimenez has been one of just a few visitors.

“It was surreal,” Jimenez said of visiting his friend in the facility. “The guard lets me in, and that’s when I see him sitting down in the middle of the room behind a low partition wall, and he says, ‘Hi David, thanks for coming to see me.’ And I said, ‘Rex, this is really bad.’”

Jimenez said that during the visit, he challenged Heuermann. “I said, ‘There’s so much evidence against you, I don’t even believe you, Rex, and you’re my friend,” Jimenez said he told his friend. “Unless you have something to explain to me and how you didn’t do it, then, come clean… If you did it, confess.”

Heuermann didn’t declare his innocence at the time, Jimenez said. “He teared up a little bit and he started crying,” said Jimenez. “I expected to hear, ‘David, I’m innocent. Can you help me out?’… And that’s when I get the feeling, I think he did it.” 

Watch Peacock’s The Gilgo Beach Killer: House of Secrets, now streaming in full, to learn much more about the case.