The remains of a former soldier wanted in the deaths of his three young daughters were believed to be found this week in the mountains of Washington state, authorities said.

Law enforcement teams have been searching for 32-year-old Travis Decker since early June, when a deputy found his truck and the bodies of his three daughters — all under age 10 — at a campground in central Washington.

Authorities are now waiting for forensic tests to confirm the identity of the remains, but the Chelan County Sheriff’s Office said on Thursday that preliminary findings suggest the remains belong to Decker.

What to know about the case:

Travis Decker’s ex-wife was worried about his mental health

A year ago, Decker’s ex-wife sought to restrict him from having overnight visits with their daughters, saying his mental health issues had worsened and that he had become increasingly unstable. She wrote in a petition to modify their parenting plan that Decker, who was an infantryman in the Army for eight years until 2021, was often living out of his truck.

The girls’ bodies were found after a scheduled visit

Authorities began looking for Decker and his daughters after he failed to return them to their mother’s home following a scheduled visit. A sheriff’s deputy found the bodies — 9-year-old Paityn Decker, 8-year-old Evelyn Decker and 5-year-old Olivia Decker — along with their father’s truck on June 2 at a campground outside Leavenworth, about 120 miles (190 kilometers) east of Seattle. An autopsy determined the girls died from suffocation, the sheriff’s office said.

The search covered a rugged terrain in Washington

Following the discovery of the bodies, more than 100 officials with state and federal agencies searched for Decker across hundreds of square miles, including mountainous and remote land. Decker had training in navigation, survival and other skills, authorities said, and once lived in the backwoods off the grid. At one point early in the search, authorities thought they spotted Decker near a remote alpine lake after receiving a tip from hikers.

Officials announced Thursday that the remains were found in a remote wooded area south of Leavenworth. They did not say when they were discovered or how far away they were from where the girls’ bodies were found.