King County Sheriff Steve Strachan said a "chilling" video diary created by Peter Keller revealed he had planned for years to kill his wife and daughter.
Officials on Thursday released the video and more details about their investigation of the double murder Keller committed in April at the North Bend home he shared with his victims.
Descriptions of the video diary were first revealed in the weeks following Keller's death at a bunker he had constructed in the mountain wilderness outside of North Bend. But the video was not released to the media until Thursday.
Strachan said it was both "breathtaking" and "evil" to discover that Keller had plotted his loved ones' murders for years.
Keller's daughter, Kaylene, 19, and her mother, Lynnettee, 41, died from gunshots to the head. Shell casings from the murder scene matched one of the guns later found in the bunker where Keller hid after the killings.
Investigators said Keller started a fire at the family's North Bend home by putting a gas can on the stove and turning it on, said Strachan. Other gas cans were placed throughout the house as "booby traps."
Investigators also found a pipe bomb, computer discs and ammunition in a safe at the house. The discs contained plans for an elaborate bunker and photos of a bunker location dating back to 2003.
Investigators enhanced one of the photos to determine the probable location of Keller's bunker during the manhunt. From this information, detectives tracked down the bunker in the wilderness near North Bend. Deputies and a SWAT team surrounded the multi-level bunker, where Keller holed himself up for several hours armed with guns and explosives.
Investigators believe Keller shot and killed himself when gas canisters were dropped into the bunker by the SWAT team.
Relatives and friends of Lynnettee and Kaylene Keller were also at the news conference to announce a scholarship fund in the victims' names. Some of the money for the fund comes from cash found in Keller's bunker. The scholarship will help those interested in computer interactive technologies, which was Kaylene's passion, at DigiPen Institute in Redmond.
"Lynnettee and Kaylene were two amazing individuals who will be missed by our family each and every day," Lynnettee's sister said.