Aug. 20 (UPI) -- DNA testing has confirmed Travis Decker, a Washington state father accused of killing his three daughters in June, is the sole suspect in the murders, authorities said Tuesday.

DNA profiles matching him were found on the plastic bags that were allegedly used to suffocate Evelyn 8, Paityn 9, and Olivia Decker, 5, the Chelan County Sheriff's Office said in a press release. No other DNA profiles were found.

"The completion of this DNA analysis provides additional evidence that indicates Travis Decker is the only suspect involved in committing these homicides," the press release said.

On June 2, the three girls were found at the Rock Island Campground along Icicle Creek with bags over their hands. Autopsies found that the cause of death was suffocation.

Authorities still are locating Decker, and a $20,000 reward is being offered for information leading to his arrest.