Laundrie family lawyer said Brian was 'visibly upset' when he left for the reserve, and his father 'wished he hadn't left but he couldn't stop him'

• The FBI and Laundrie's family attorney confirmed the remains of Brian Laundrie on Thursday.
• Attorney Bertolino said Brian's father wishes he could have stopped his son from leaving.

In an interview with NBC News on Thursday, the Laundrie family attorney Steven Bertolino said that before Brian Laundrie left his parents' home to the Carlton Reserve he was "visibly upset," and his father could not stop him.

"Brian was upset when he left," Bertolino said. "Chris conveyed to me several times that he wished he hadn't left but he couldn't stop him."

The FBI and the attorney for the Laundrie family confirmed Thursday that the "skeletal remains" found - including a "partial skull" according to the NBC News interview - belonged to Brian Laundrie. Authorities were able to use Laundrie's dental records as confirmation.

Bertolino said that the park was submerged underwater, making it completely "inaccessible" until this week.

Laundrie's parents, Chris and Roberta, who found their son's belongings, decided to check the park after learning it had re-opened, but this was not their first time participating in the search, their attorney also said.

Brian Laundrie was the sole person of interest in the disappearance and death of his 22-year-old fiancée Gabby Petito, who was reported missing by her family on September 11, after Laundrie returned to their Florida home without her on September 1. The two had been on a cross-country road trip in a converted van.

Petito's remains were found on September 19; her death was later ruled a homicide and the manner of death was determined to be strangulation.

Brian was reported missing by his family on September 17, after going for a hike in the reserve where his body was found several days prior.

Bertolino also responded to conspiracies during the interview, maintaining that the "Laundrie family has coordinated with law enforcement since day 1."

"Perhaps when certain conversations wrap up there will be communications with the family," Bertolino said. "I've talked to Richard Stafford, the lawyer for the Petito and Schmidt family in the past."