“We are waiting for medical examiner confirmation but we have reason to believe that they are Patrick Shunn and Monique Patenaude,” Snohomish County Sheriff’s Office spokeswoman Shari Ireton said at a news conference.
Authorities had been searching for the couple since they were reported missing April 12.
Ireton said deputies had searched in the area where the bodies were found but that getting specific information about where they were buried was what helped them make the discovery.
Tony Clyde Reed, one of two brothers charged with the slayings, has been cooperating with detectives, Ireton said.
Reed appeared in Snohomish County Superior Court earlier Tuesday afternoon and entered not guilty pleas to two counts of first-degree murder and unlawful firearm possession in the case.
He turned himself in last week at the U.S.-Mexico border after a monthlong manhunt.
His attorney, James Kirkham, helped arrange the surrender. Kirkham told The Daily Herald in Everett, Washington, on Monday that his client turned himself in to answer the allegations against him.
“My client is innocent of the first-degree murder charges,” the lawyer said. “He’s here to defend himself.”
Authorities are still searching for Reed’s 53-year-old brother, John Blaine Reed.
John Reed lived up an old logging road from the couple’s 21-acre spread in the foothills of the Cascade Mountains. When Patenaude and Shunn sued other neighbors over a property dispute more than two years ago, they avoided naming him as a defendant because they didn’t want to irk him, their former lawyer, Thomas Adams, said previously.
John Reed had threatened to shoot the couple for cutting brush between their two properties in 2013, according to court documents.
The land abutted the nation’s worst landslide disaster, the 2014 Oso landslide, which wiped out a rural neighborhood and killed 43 people. In an interview shortly afterward, John Reed told The Seattle Times he watched as the slide roared past his front yard.
The county recently bought out Reed’s house to ease risks from future flooding, but investigators believe Reed had been returning to the home since then.
According to charging documents, John Reed was upset that his property had been condemned, and he recently had been angry because the couple had complained that he was squatting at his old house, prompting authorities to warn him to leave.