Duane Chapman, also known as Dog the Bounty Hunter, believes that Brian Laundrie has made himself a murderer by reading "demonic" serial killer books.

The 68-year-old reality star told The Sun that he thinks the "dark side" books that Gabby Petito's fiance read as a child could have influenced him to be a killer. Chapman said this is what happens when children are looking at these kinds of things. 

"[It] catches on, and it's demons, and it's blood, and it's this and that, look what that led to," he noted, adding that Brian has "obviously" taken these books to heart.

Dog the Bounty Hunter also believes that Gabby Petito's fiance did not become a killer "overnight." He said a killer is made, and Laundrie is "built to be a killer." Chapman further noted that he's also thinking about Laundrie possibly being a "serial killer" and not just Petito's killer.

Brian Laundrie previously boasted on Instagram that he and Petito had read Chuck Palahniuk's novels "Lullaby" and "Rant." "Lullaby" recounts the story of Carl Streator, who is a journalist writing an article about crib death. Streator then noticed a strange connection between the deaths of babies and those of his wife and infant.

The journalist then finds out that his wife and kid had died after reading them a "culling song" from a book. He unintentionally memorized the rhyme and became a serial killer who kills people over minor annoyances.

"Rant" centered around a high school rebel, Buster "Rant" Casey. It takes the form of an oral history of Casey, in which friends, admirers, enemies, and relations have their say on this evil character, who may "be the most efficient serial killer of our time."

Brian Laundrie wrote on Instagram that it was the "craziest out of all of Chuck's books" on his shelf. Laundrie added that he and Gabby Petito had read the story aloud, and he could not believe some of the stuff coming out of their mouths.

Laundrie's Instagram page also displays depictions of blood, knives, and grim reapers. He also appears to have a Pinterest profile with some pinned images depicting death and violence, sketches of skulls, and pictures of The Joker, Frankenstein, and The Invisible Man.

READ NEXT: Gabby Petito, Brian Laundrie Supposed Beach Wedding in Florida Cancelled Due to COVID Pandemic   

Dog the Bounty Hunter Says Brian Laundrie's Life Will Be 'Hell in Jail'

Dog the Bounty Hunter also told The Sun that other prisoners would make Brian Laundrie's life "hell in jail" once police arrested him. He also believes that Gabby Petito's fiance is still alive.

Duane Chapman said he does not think Laundrie has the guts to kill himself and does not think "he's that personality." Dog the Bounty Hunter also said that he believes it's only a matter of time before investigators capture Laundrie.

He also alleged that the Florida fugitive would soon be charged for Petito's death even though Laundrie was not currently considered a suspect. Duane Chapman believes that Laundrie committed a "terrible crime," and might get 20 years in prison "and do 11."

However, Dog the Bounty Hunter said "cowboys" inside a Wyoming penitentiary do not like it if someone kills a girl or a child.

"Almost every penitentiary in America don't like if you kill a girl or child so he was going to have, as they would say in Wyoming, hell to pay," Chapman noted.

Brian Laundrie's Attorney Says Gabby Petito's Fiance is Not a Suspect

Last week, Brian Laundrie's attorney, Steve Bertolino, said his client has not been charged and was not even a suspect in Petito's homicide. The FBI has issued a federal arrest warrant for Laundrie but over debit card fraud.

"Brian is only considered a person of interest in relation to Gabby Petito's demise... At this time Brian is still missing and when he is located we will address the pending fraud charge against him," Bertolino noted.

Brian Laundrie was named a person of interest by North Port police after returning home on September 1 or 10 days before Gabby Petito was reported missing by her family.

Petito disappeared on a cross-country road trip with Laundrie. The couple was traveling to Oregon when the YouTuber stopped communicating with her family in Wyoming in late August.

Petito's body was found at the Spread Creek Dispersed Campground near Grand Teton National Park in Wyoming on September 19.

Teton County, Wyoming coroner Brent Blue said Petito was strangled to death by "human force," and the manner of death was homicide.

Dog the Bounty Hunter has been searching for Gabby Petito's fiance since late last month. Authorities are still trying to locate Brian Laundrie after he was reported missing on September 17. 

Laundrie's parents said they last saw him on September 13, leaving home to go to the Carlton Reserve area for a hike.

READ MORE: Brian Laundrie Manhunt: Parents of Gabby Petito's Fiancé Change the Date of Florida Fugitive's Disappearance

This article is owned by Latin Post.

Written by: Mary Webber

WATCH: Here's Where Dog the Bounty Hunter Thinks Brian Laundrie Is - From Fox 13 Tampa Bay