King County sheriff's detectives said in court documents that Joseph McEnroe told them "I didn't want them to turn us in" after he and Michele Anderson allegedly shot her parents to death in their home in rural Carnation.
The Seattle Times said Saturday that McEnroe and Anderson allegedly killed Wayne and Judith Anderson due to family tensions and then waited to ambush Scott and Erica Anderson and their two children who were en route to spend Christmas Eve at the house.
The two suspects face arraignment Jan. 9. Prosecutors said Friday they were considering seeking the death penalty.
Meantime, KING-TV Seattle said Saturday that relatives of the victims were calling for the resignation of two deputies who responded to a 911 call at the home, but didn't go past a locked gate on the driveway. The call apparently came from gravely wounded Erica Anderson, who could not speak before McEnroe hung up the phone.