Brian Laundrie could be a serial killer

Dog the Bounty Hunter speculated in a new interview that Brian Laundrie — the sole person of interest in the death of his girlfriend, Gabby Petito — could be a “serial killer.”

“I’m thinking more and more about him being maybe a serial killer — not just a killer of Gabby. The books he reads are unbelievable,” Dog, whose real name is Duane Chapman, told the Sun.

The 68-year-old celebrity TV star — who has been on the hunt for Laundrie, 23 — claimed to have uncovered the fugitive’s “demonic past” and his obsession with the “dark side,” according to the news outlet.

He cited the kinds of disturbing books the couple had allegedly read.

“A couple of the books that he’s been reading are 10 times worse than ‘Dungeon and Dragons.’ This kid, Brian, has taken those books obviously to heart. And this is what happens when your kid is looking at those kinds of things,” he told the Sun.

“He just overnight just didn’t become a killer. A killer is made, and he is built to be or she, a killer,” Chapman continued. “He built himself to be that by looking at that kind of, let’s say the dark side stuff. There are pictures of demons all over it.”

Laundrie once boasted about reading a book about a serial killer and wrote on Instagram that he and Petito had read the 2002 horror-satire novel “Lullaby” by Chuck Palahniuk, the news outlet reported.

“The f—- craziest out of all of Chuck’s books on my shelf, I can’t fathom how he must have written this one! I’d love to preach all of the insane twists and turns but all I can say is that I’ll never forget the name Rant Casey. Or Green Taylor Simms,” he wrote.

“Me and my fiancé read this one out loud together and boy oh boy I can’t believe some of the stuff coming out of our mouths,” Laundrie added.

Palahniuk’s novel is about a journalist who is writing an article about crib death when he notices a strange connection between babies’ deaths and those of his own wife and infant.

The journalist, Carl Streator, finds out that his family had died after he read them a “culling song” from a book — then starts killing people over minor annoyances after he memorizes the rhyme.

Online sleuths also came across some chilling posts by Laundrie in social media, including one from last year that featured an image of ghoulish figures with scythes.

“Grim Reaper leading sheep to the slaughter,” he reportedly wrote.

Meanwhile, Dog’s daughter Lyssa Chapman teased that “big news” would be released soon about the search for Laundrie.

“I’m hoping tomorrow I’ll be able to share some BIG news with you guys,” she wrote Thursday, according to the Sun. “Having to stay tight-lipped for now … trust the process.”