This Key Finding Is Now The Focus Of The Brian Laundrie Search: Report

Remnants of a campsite that appeared to have been recently used at a Florida reserve have reportedly become the focus in the search Brian Laundrie -- the fiancé of Gabby Petito and a person of interest in her death -- a source close to the Laundrie family told CNN's Chris Cuomo on Wednesday (October 8).

Law enforcement had previously asked Christopher Laundrie, Brian's father, to show them trials that his son would have typically used, but then notified him that they wanted to search the area alone after the recent discovery of the remnants.

Carlton Reserve, a 24,565-acre campsite located in Venice, Florida, is currently closed to visitors while authorities search the area.

North Port Police told CNN the FBI was leading the search for Laundire and would be responsible for making decisions or taking actions in relation to the case.

"The FBI would have to answer if that was true," said Josh Taylor, spokesperson for the police department.

Laundrie family attorney Steve Bertolino told CNN that Christopher Laundrie was asked to help North Port Police during their search for his son on Wednesday (October 6) before police decided to postpone those plans.

"Chris Laundrie was asked to assist law enforcement in their search for Brian at the preserve today," Bertolino said via CNN. "Since the preserve has been closed to the public Chris has not been able to look for Brian in the only place Chris and Roberta believe Brian may be. Unfortunately North Port police had to postpone Chris' involvement but Chris and Roberta are hopeful there will be another opportunity to assist."

Bertolino also said Brian Laundrie's parents "don't believe he's in another area. They believe he is in the preserve."

On Tuesday (October 5), Laundrie's sister, Cassie, said she doesn't know where her brother is and would "turn him in" if she did in an exclusive interview with ABC News.

Cassie Laundrie said she last heard from her brother on September 6 -- after he returned from his cross country trip without Petito -- when the family went to Fort De Soto Park in Pinellas County, Florida.

"We just went for a couple of hours and we ate dinner and had s'mores around the campfire and left, and there was nothing peculiar about it," she said. "There was no feeling of grand goodbye. There was no nothing."

"I'm frustrated that, in hindsight, I didn't pick up on anything," she added. "It was just a regular visit."

Cassie added that it's unusual for Brian to disappear this long, having initially been reported missing on September 17, days after Petito's parents initially reported her missing.

"I worry about him. I hope he's OK, and then I'm angry and I don't know what to think," she said. "I hope my brother is alive because I want answers just as much as everybody else."

Cassie said she's cooperated with authorities during their investigation "since day one" and believes her parents should do the same, noting that she's unsure of their role.

"I don't know if my parents are involved," she said. "I think if they are, then they should come clean."

On September 30, police released additional bodycam footage which shows Petito telling an officer that an argument with Laundrie got physical.

The newer footage stems from the incident on August 12 in Moab, Utah in which police made contact with Petito -- whose remains were found on September 19 -- and Laundrie -- a person of interest in her death whose whereabouts are currently unknown.

A bystander called the Moab Police Department and reported seeing a man hitting a woman. Officers pulled over the van Laundrie and Petito were traveling in on their cross-country trip and Petito told officers that she intially slapped Laundrie before he retaliated.

"I guess, but I hit him first," Petito said when asked by an officer if Laundrie hit her in the face.

"Where did he hit you? Don’t worry. Just be honest," the officer asked.

"Well, he grabbed my face," Petito said.

"Did he slap your face? Or what?" the officer responded.

"Well like, yeah he grabbed me with his nail, and I guess that’s why I definitely have a cut right here because I can feel it when I touch it, it burns," she said, while holding her jaw and crying.

The video then shows Laundrie recanting his side of the incident.

"She gets really worked up, and when she does she swings, and she had her cellphone in her hand, so I was just trying to push her away," Laundrie said.

The new video adds to previously released bodycam footage showing the couple addressing the incident with police, which an officer described as a mental health crisis, not a domestic assault, according to a police report.

The city of Moab announced on September 28 an independent investigation will be conducted on officers' handling of the situation involving Petito and Laundrie.

Last month, an arrest warrant was issued for Laundrie after a grand jury indicited him for his "use of unauthorized devices" during the events following the death of Petito.

The indictment obtained by CNN accuses Laundrie of using a debit card and PIN number for accounts that didn't belong to him between August 30 to September 1 in order to make purchases totaling more than $1,000.

A source close to Laundrie's family told CNN the 23-year-old left his own wallet and cell phone behind when he was last seen leaving his parents' Florida home 10 days ago after he initially returned to the area from a cross-country road trip without Petito, who was reported missing on September 11.

The source added that Laundrie's parents were concerned he might harm himself at the time he left their home.

An attorney for Laundrie's family emphasized that the arrest warrant isn't related specifically to Petito's death, rather incidents committed by Laundrie afterward.

"It is my understanding that the arrest warrant for Brian Laundrie is related to activities occurring after the death of Gabby Petito and not related to her actual demise," Steve Bertolino said in a statement. "The FBI is focusing on locating Brian and when that occurs the specifics of the charges covered under the indictment will be addressed in the proper forum."

"While this warrant allows law enforcement to arrest Mr. Laundrie, the FBI and our partners across the country continue to investigate the facts and circumstances of Ms. Petito's homicide," added FBI Special Agent in Charge Michael Schneider. "We urge individuals with knowledge of Mr. Laundrie's role in this matter or his current whereabouts to contact the FBI."

On September 24, local and federal authorities continued to search for Laundrie in the Carlton Reserve, a nature preserve estimated to be around 25,000 acres, in North Port near his family home after pausing September 23 due to darkness.

Duane 'Dog the Bounty Hunter' Chapman has inserted himself into the search for Laundrie and told TMZ Monday (October 4) that he believes Laundrie is "alive" but not "doing well."

Chapman said Laundrie showed "no evidence" of being suicidal and credited Laundrie's social media presence for his theory.

"If you go to his Instagram pages and look what kind of person he really is and the books that he reads and especially a very favorite book, that's not books for sucidal people," Chapman said.

On Sunday (October 3), Chapman tweeted a video update of himself wading through the Florida swamp waters in search for Laundrie.