ST. PETERSBURG, Fla. >> The FBI today identified human remains found in a Florida nature preserve as those of Brian Laundrie, a person of interest in the death of girlfriend Gabby Petito while the couple was on a cross-country road trip.

The remains, a backpack and notebook believed to belong to Laundrie were discovered Wednesday in a Florida wilderness park, according to the FBI. The area where they were found had been under water during earlier searches.

The FBI’s Denver office said in a news release a comparison of dental records confirmed that the remains were Laundrie. A lawyer for his parents, Steve Bertolino, also confirmed in a statement they were told the remains were those of their son.

“We have no further comment at this time and we ask that you respect the Laundrie’s privacy at this time,” the statement said.

The FBI statement did not list a cause of death. It wasn’t clear how long the remains may have been submerged in water.

The discovery of the remains concluded a massive search involving federal, state and local law enforcement that began shortly after Laundrie disappeared Sept. 14, two weeks after the 23-year-old returned alone to his parents’ home in North Port, Florida.

The investigation into Petito’s slaying, however, is not yet concluded. But only Laundrie has ever been identified by law enforcement officials as a person of interest in the case.

Petito’s family reported her missing Sept. 11, launching a search that garnered worldwide media attention and, in Laundrie’s case, focused largely on the Carlton Reserve wilderness park near the Laundrie home. It is a densely wooded, swampy area that’s home to alligators, coyotes, bobcats, snakes and numerous other creatures.

The couple first met as teenagers on Long Island, New York, and more recently moved to Florida’s Gulf Coast to live with his parents.

They first gained an online following while on their trip in a converted Ford Transit van in videos filled with happy scenes that may have concealed deeper problems. After Petito disappeared, the case became a true-crime obsession on social media.

The intense focus on Petito’s case has led to renewed calls for people to pay greater attention to cases involving missing Indigenous women and other people of color. Petito, 22, was white.

Her body was found Sept. 19 on the edge of Wyoming’s Grand Teton National Park, which the couple had visited. The coroner there concluded she died of strangulation and her body had been where it was found for three or four weeks.

The couple was stopped Aug. 12 by police in Moab, Utah, after they had a physical altercation, but no domestic violence charges were filed. The police department there is conducting an internal review to determine if policy was followed.

Laundrie returned home alone Sept. 1 in the van the couple took on their trip, which was later impounded by authorities. He was reported missing after telling his parents that he was going for a hike in the Carlton Reserve.

Dozens of unconfirmed tips poured into authorities about spotting Laundrie from Wyoming to the Appalachian Trail, but none panned out.

The remains were found Wednesday as searches concentrated on the nearby Myakkahatchee Creek Environmental Park, where a Ford Mustang that Laundrie drove to the wilderness was found. That park is directly adjacent to the Carlton Reserve, both of which are about 35 miles (56 kilometers) south of Sarasota, Florida.

Laundrie was charged in a federal Wyoming indictment with unauthorized use of a debit card, which alleged Laundrie used a Capital One Bank card and someone’s personal identification number to make unauthorized withdrawals or charges worth more than $1,000. It does not say to whom the card belonged or what type of charges were made.

Had Laundrie lived, that indictment would have permitted authorities to arrest him.