Gabby Petito's best friend says Brian Laundrie once lived in the Appalachian mountains by himself 'for months'

• Gabby Petito's best friend Rose Davis said Brian Laundrie can survive in the wilderness.
• Davis told People that Laundrie once stayed in the Appalachian mountains by himself "for months."
• "He is out in the wilderness, I promise you," she said.

Gabby Petito's best friend Rose Davis says Brian Laundrie can survive out in the wilderness because he has done it before. Davis told People in an interview that Laundrie, who is a person of interest in his fiancée Petito's death, once stayed in the Appalachian mountains by himself "for months."

"He is out in the wilderness, I promise you," Davis, 21, told People. "He's out there. He is. If he's alive, he's out there, camping out ... He lived in the Appalachians by himself for months."

Petito, 22 years old, was reported missing on September 11 by her mother, Nicole Schmidt.

Petito and Laundrie had been traveling around the US in a van and documenting their experience on social media, but he returned to their home in Florida without her.

This week, the FBI's Denver office confirmed on Twitter that human remains were discovered in a remote area in Bridger-Teton National Forest in Wyoming, and they belonged to Petito. They ruled her death a homicide.

Police are searching for Laundrie, 23, in Carlton Reserve in Florida after his parents reported him missing on September 17. He reportedly left his parents' home without his phone or wallet, a source told CNN, which makes him harder to locate.

The US District Court of Wyoming issued a federal arrest warrant for Laundrie on Wednesday concerning his activities following the death of Petito, according to the FBI.

Friends of Petito and Laundrie have been vocal about the couple as the story has developed. They have said the couple's relationship had "very high highs and very low lows." Body camera footage released by police in Utah, dated August 12, showed officers responding to a fight between Laundrie and Petito, who was crying.

Davis previously told New York outlet News 12 that Laundrie was controlling, manipulative, and jealous.

"He was always charismatic and making Gabby breakfast almost every morning, but you know, you can see the jealousy side," she said.

"He also wanted what he wanted when he wanted it, and he'd find a way to get it. Not in a violent manner, but if he didn't want Gabby to do something, he'd find a way to make it so she couldn't do it."