Brian Laundrie died from a gunshot wound to the head, according to family attorney Steven Bertolino.
After a month-long search for the 23-year-old fugitive, his remains were found near his belongings in Florida’s Carlton Reserve in an area that was previously underwater in October.
His death has been ruled a suicide.
Brian was named a person of interest in his fiancée Gabby Petito’s disappearance.
Gabby and Brian had recently quit their jobs to travel across the United States in a van, vlogging their adventures for their YouTube channel.
But just weeks later, Brian returned home to Florida in the white van without his wife-to-be and ten days later, Gabby’s family in New York reported her missing.
The body of the 22-year-old was found at a forest in Wyoming on September 19.
According to a local coroner, Gabby was killed by strangulation about three to four weeks before her body was found.
Shortly before her disappearance, Gabby and Brian were pulled over by police in Moab, Utah, following reports of a domestic dispute.
In a 911 audio recording provided by the Grand County Sheriff’s Office, a caller claimed they were driving by a white van with a Florida license plate when they saw “the gentleman was slapping the girl”.
The caller explained: “Then we stopped. They ran up and down the sidewalk. He proceeded to hit her, hopped in the car and they drove off.”
Moab Police Department Chief Bret Edge said his officers responded to the incident, located the van and pulled the couple over.
The police released the bodycam footage of the traffic stop, which showed Gabby crying in the van before being asked to step out of it.
When asked by police why she was crying, the 22-year-old said: “I’m just crying because we’ve been fighting this morning. Just personal issues.”
Gabby also admitted to slapping her fiancé, who had scratches on his face, but insisted she didn’t mean to harm him.
According to the police report, the couple stated that Brian did not hit Gabby.
Chief Bret Edge said: “Insufficient evidence existed to justify criminal charges.”
The police officers on scene suggested that the couple spend the night apart, organising a hotel room for Brian and advising Gabby – who the report describes as “confused and emotional” – to spend the night in the van. It is understood the couple did so.
Brian, who had refused to talk to North Port police on the advice of his lawyer, had not been seen since September 14, when he told his parents he was going for a hike in the nearby Carlton Reserve wilderness area.
On September 22, a federal arrest warrant was issued for Brian Laundrie relating to his alleged activities following Gabby’s death.
The indictment accused him of using an unauthorised debit card and bank account between August 30 and September 1.
Following news of Brian’s cause of death, the Laundrie family attorney told PEOPLE in a statement: “Chris and Roberta are still mourning the loss of their son and are hopeful that these findings bring closure to both families.”