SNOHOMISH COUNTY, Wash. -- It's been more than 10 years since Mary Cooper and her daughter Susanna Stodden were shot dead while hiking the Pinnacle Lake Trail outside of Granite Falls. But it's only been days since David Stodden, Mary's husband and Susanna's father, was cleared as a suspect in their grisly deaths.
The Snohomish County Sheriff's Office said new detectives have been assigned to the cold case. Those detectives asked David Stodden to submit to a polygraph -- his third since the investigation began.
Stodden passed the latest lie detector test. The first two polygraphs came back inconclusive.
"It's kind of insulting when someone wants you take a polygraph when its your own family, and since I had already taken it twice I didn't want to take it again," Stodden said. "They pretty much said they weren't going to work on the case until I took a polygraph, so I finally decided to take it."
Hikers found Mary Cooper and Susanna Stodden dead two miles up the Pinnacle Lake Trail off of Mountain Loop Highway, just outside Granite Falls, on July 11, 2006. Both had been shot in the head.
The seemingly random backcountry murder rattled avid hikers. At first, detectives received hundreds of tips, but 12 years later, there are still no leads or suspects. David Stodden has been frustrated with the investigation in the past, so much so that he took out a newspaper ad in 2015 asking for help from the public. Watch a 2015 interview with David Stodden here:
"I am sure somebody must know something or have heard of something by now,” Stodden told Q13 in 2015.
Detectives have said that evidence indicates the murders were random. David Stodden said no one really knew where Mary and Susanna were going that day. He said they also changed their destination while hiking.
"They had no enemies at all," he said.
Anyone with information is asked to call the Snohomish County Sheriff’s Office at (425) 388-3845.