Brian Laundrie is still missing, and a source close to his parents revealed that they are worried that he would hurt himself.

While speaking with CNN, the source also confirmed that Laundrie left his family home in Florida on Sept. 14 without his wallet and cell phone. However, he took his backpack with him.

Days later, Laundrie's parents reported him missing and alerted authorities. But when they searched for Laundrie in the nature reserve close to his home, they were unable to find him.

What happened to Gabby Petito?

Last week, authorities said they had decided to stop searching for Laundrie because they had already exhausted their options. But after his fiancée Gabby Petito's body was found, they decided to resume their search.

On Sunday, the FBI found the remains of a woman whose description matched Petito's. And on Tuesday, they were able to confirm that the remains belonged to the travel vlogger.

The FBI also ruled her death as a homicide, and her family wants to know what happened to the 22-year-old.

Laundrie and Petito embarked on a cross-country trip by land in June. And reports revealed that witnesses spotted them arguing at a restaurant days before Petito disappeared.

A source said that she and her boyfriend saw Laundrie and Petito arguing with a waitress from the local restaurant. And the owner confirmed that Laundrie and Petito dined with them last month.

Police body cameras also showed a hysterical Petito crying on the road following an altercation with Laundrie. She told officers that they got into a fight, and she scratched her fiancé.

Another source also claimed to have seen Laundrie driving slowly around the area where Petito's body was found. And he reportedly left Petito's van in the same area days later.

Read Also: Witness Claims Brian Laundry Aggressively Fights With Gabby Petito At Wyoming Restaurant Before Van Life Influencer Vanished

Brian Laundrie issued a federal arrest warrant

Meanwhile, a federal arrest warrant was issued to Laundrie after he was indicted for his use of unauthorized devices on Aug. 30 and Sept. 1. Police officials believe that Laundrie's unauthorized use of bank cards happened after Petito's demise.

FBI Special Agent in Charge Michael Schneider posted a statement regarding the federal arrest warrant on Twitter.

Laundrie reportedly used a debit card and pin number for accounts that did not belong to him. And he debited over $1,000 from the account within a span of two days.

In his statement, Schneider also urged those who may have information regarding Laundrie's whereabouts to reach out to them.

A lawyer for Petito also said that the federal warrant issued to Laundrie has nothing to do with his client's death.

"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. 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," Steve Bertolino said via NBC News.

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