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() The bloody handprint found on the pickup truck of a Washington state father sought in connection with the killing of his three young daughters appears to be adult-sized, the sheriff leading the manhunt said Wednesday.

Chelan County Sheriff Mike Morrison told that the handprint discovered on the back of Travis Decker’s truck “was about the size of an adult handprint,” but authorities are unsure whether it came from Decker or someone else who may have been at the scene.

“We’re not ruling anything out,” Morrison said on ’s “Banfield,” adding that crime lab teams collected samples and spent several hours processing the scene where the girls’ bodies were found.

Girls found with zip ties, plastic bags over heads

The bodies of Paityn, 9; Evelyn, 8; and Olivia, 5, were discovered Monday afternoon near a campground west of Wenatchee, about 100 yards from their father’s abandoned pickup truck.

Court documents indicate the girls died from asphyxiation and were found with zip ties around their wrists and plastic bags over their heads, NBC News reported.

The sisters were last seen Friday evening when they left for a custodial visit with their father. Their mother reported them missing around 8 p.m. when Decker failed to return them as scheduled.

Police still searching for girls’ father Travis Decker

Morrison said multiple agencies are involved in the search for Decker, 32, including the U.S. Marshals Service, FBI, Border Patrol, Homeland Security Investigations and Washington State Patrol. The search involves drones with thermal imaging, cadaver dogs and ground units.

Authorities are also analyzing cellphone tower data and electronic devices found at the scene, Morrison said. A $20,000 reward has been offered for information leading to Decker’s arrest.

Decker’s military training and survival skills are complicating the manhunt in the mountainous, wooded terrain of Chelan County, Morrison said. The suspect served in the Army starting in 2013 and transferred to the Washington National Guard in 2021.

Morrison said Decker’s father told investigators that his son had enjoyed spending time in the wilderness since childhood, sometimes for months at a time, and was known to cache supplies in remote areas.

“If he did set it up beforehand and put supplies out there, it could make it more difficult to track him down,” Morrison said.

Morrison confirmed there had been a possible sighting of Decker but declined to provide details. He described the suspect as 5 feet, 8 inches tall and 190 pounds with black hair and brown eyes. Decker was last seen wearing a light-colored shirt and dark shorts.

Police have warned the public that Decker should be considered dangerous and not to approach him if spotted.

‘s Jeff Arnold and The Associated Press contrbited to this report.