Brian Laundrie's parents are 'not convinced' yet that the human remains authorities found belong to their son

• Brian Laundrie's parents are "not convinced" yet that the human remains found are their son's.
• But they believe there's a "strong" chance the remains are his, a family attorney told Insider.

Brian Laundrie's parents are "not convinced" yet that the human remains found in a Florida park belong to their missing son - a person of interest in the killing of his fiancée Gabby Petito - but they believe there's a "strong" chance the remains are his, the family's attorney told Insider on Thursday.

Lawyer Steven Bertolino said that Laundrie's parents, Chris and Roberta, are "just waiting" for forensic experts to identify the suspected remains.

The FBI told reporters Wednesday that "what appears to be human remains" were discovered, along with a backpack and notebook belonging to Brian Laundrie, in the heavily wooded area where authorities have been searching for the 23-year-old for more than a month.

"These items were found in an area that up until recently had been underwater," Michael McPherson, the special agent in charge of the FBI's Tampa field office, said during a press conference at the entrance of the Myakkahatchee Creek Environmental Park in North Port.

The 160-acre park connects to the sprawling 25,000-acre Carlton Reserve where Laundrie's parents have told investigators that their son went for a hike on September 13 and never returned to their North Port home.

The parents formally reported Laundrie missing on September 17, more than two weeks after investigators say he returned home from a cross-country road trip without 22-year-old Petito and with the van the couple had been traveling in.

Petito's body was discovered at a remote campsite in Wyoming on September 19. A coroner later determined her manner of death was homicide and the cause was manual strangulation.

In late September, the feds issued an arrest warrant for Laundrie on a bank-card fraud-related charge for allegedly using Petito's debit card without authorization following her death.

Authorities found the human remains where Laundrie's parents 'advised' they should look

The apparent human remains found in Florida on Wednesday were at a location Laundrie's parents had "advised" authorities to search for him, Bertolino previously said.

"Chris and Roberta Laundrie were at the reserve earlier today when human remains and some of Brian's possessions were located in an area where they had initially advised law enforcement that Brian may be," Bertolino said.

He explained that Brian Laundrie's father found a "dry bag" in the woods alongside a trail containing some of his son's belongings.

"A law enforcement officer also found a backpack nearby on the side of the trail near the remains," Bertolino said.

Bertolino told Insider on Thursday that it is "common sense" to believe that the remains belong to Laundrie.

"Brian's belongings found near remains in an area of [the] park [the] parents knew he frequented," the attorney said.

Local police said they worked in 'treacherous conditions' to find the remains

Meanwhile, local law enforcement officials addressed the media presence at the Florida park on Thursday - where authorities were still searching - and detailed the "treacherous conditions" that investigators have been working through in the hunt for Laundrie.

"We're talking about water levels up above almost the chest area, rattlesnakes, moccasins, alligators - and these heroes go out there," Lee County Sheriff Carmine Marceno said. "While we can't change the outcome, we can bring justice."

North Port Police Chief Todd Garrison added, "It's challenging times and I know everybody wants to know exactly what's going on every second possible."

"All of America is watching, OK, but we'll never, never jeopardize an investigation to give that information out until the time is right," he said.

Garrison said the conditions in the park and reserve "are very, very difficult."

"It's not like your searching a house or a car," he said. "These areas are huge and they're covered by water."