Travis Decker: FBI finds possible evidence in search for fugitive dad accused of killing three children

Authorities have uncovered potential new evidence in the desperate search for fugitive father Travis Decker, who vanished three months ago after allegedly murdering his three young daughters during a custody visit in Washington State.

This week, FBI investigators scoured Rock Island Campground in Leavenworth, just four miles from where Mr Decker is accused of suffocating his children — Paityn, nine, Evelyn, eight, and Olivia, five.

The girls were discovered zip-tied with plastic bags over their heads, a crime that has horrified the community and triggered one of the region’s most extensive manhunts.

More than 100 officers from federal, state, and local agencies were deployed in what officials described as the largest search ever undertaken in the Leavenworth area, combing one million square meters of rugged terrain over two days.

During the operation, search teams reported finding bones in a 200-acre section of the campground. It remains unclear whether the remains are human, but analysts will conduct examinations, The Sun reported.

Investigators also uncovered the body of what appeared to be an overdose victim, as well as several other items of interest, though the FBI has not confirmed whether they are linked to Mr Decker.

“Finding this potential evidence emphasises the value in having various teams search an area multiple times, especially in such challenging conditions,” said W. Mike Herrington of the FBI’s Seattle field office.

The area around the campground was temporarily sealed off, with barriers erected on nearby trails, but has since reopened.

Mr Decker, a former military man, has remained elusive since May 30, when he collected his daughters for a scheduled custody visit but failed to return them to their mother.

Days later, his abandoned truck was discovered at Rock Island Campground, spattered with blood and containing two bloody handprints. Nearby, police made the grim discovery of the girls’ bodies.

Forensic analysis has since linked Mr Decker’s DNA to the bags used to suffocate his children, strengthening the case against him. He now faces charges of kidnapping and murder, with authorities warning he should be considered armed and dangerous.

Chelan County Sheriff Mike Morrison insisted investigators will not let up: “He’s got to be perfect every single day. We just have to be perfect once.”

Mr Morrison added that if Mr Decker is still alive, “he must be pretty tired,” but stressed police are determined to bring closure for the victims’ family.

“If it’s not me wearing this uniform, it’s another Chelan County Sheriff. We will find him, in one fashion or another.”

Authorities have acknowledged the possibility that Mr Decker may have had help evading capture, though they urged anyone assisting him to reconsider. A $20,000 ($A30,600) reward is being offered for information leading to his arrest.

Despite numerous alleged sightings and fresh images released in July, no credible lead has yet brought investigators closer to capturing Mr Decker.

The hunt for him continues.