Brian Laundrie Seen 'Slamming Doors' and 'Acting Like a Lunatic' on Road Trip Weeks Before Gabby Petito's Death, Witness Claims

Brian Laundrie was reportedly spotted crying and acting erratically only a few weeks before Gabby Petito's murder.

According to a newly-released FBI report, a witness said he was driving past a couple parked in a van on the side of the road when he thought he saw a young man slap a woman on August 12, 2021.

Concerned, the witness turned his own vehicle around and parked somewhere he could watch the couple for around 15 minutes to make sure everything was alright. During that time, he told authorities that he witnessed someone who he "believed" to be Laundrie "acting like a lunatic," noting he'd been "sporadically opening and slamming doors" and "pacing around their van."

"[Laundrie] seemed to be pleading with the female and at one point may have tried to hug the female, but was pushed back by her," the report continued. "The male ultimately pushed the female’s legs into the passenger side of the van, closed her door and entered the driver’s side of the vehicle."

At one point, the witness alleged "both passengers appeared to be crying."

Despite being worried, the driver said he decided against calling 911 because he'd already done so earlier that same day when he was almost ran off the road by another vehicle. However, several weeks later, he did contact the FBI when Petito's disappearance made headlines.

This encounter is believed to have occurred only a few minutes before Moab police spoke with Laundrie and Petito.

As OK! previously reported, the late travel blogger was last seen alive on August 27, 2021. Days later, Laundrie quietly returned home to Florida on September 1, 2021. The 22-year-old's family finally reported her missing on September 11, 2021, after not being able to get in contact with her or get any information on her whereabouts from Laundrie's family.

On September 19, 2021, Petito's body was found in Grand Teton National Park in Wyoming. Her cause of death was ruled to be strangulation.

During the search for Petito, Laundrie disappeared and later took his own life. When his body was discovered in a Florida reserve, a journal was also found in which he confessed to killing her after she allegedly sustained an injury on their road trip.

"I ended her life, I thought it was merciful, that it is what she wanted, but I see now all the mistakes I made," he wrote. "I panicked, I was in shock. But from the moment I decided, took away her pain, I knew I couldn’t go on without her."

The New York Post reported details of the FBI report.