(CNN) -- A video diary released Thursday gives an eerie view into the planning process of a man police say murdered his wife and daughter and then killed himself in a bunker he built in the woods in Washington state.
Peter Keller, 41, shot and killed his wife, Lynnettee Keller, and their 18-year-old daughter, Kaylene Keller, and then set a fire in their Seattle-area home in April, the King County Sheriff's Office said. A video diary Keller left behind touched on his decision to kill his family but still gave little information about his reasons.
"A while ago I used to sit here and think, you know, this whole thing is crazy," Keller said as he wandered in the woods wearing a gray sweatshirt, his hair disheveled. "The more I thought about it. The more I understand it. I don't really feel bad about it. It is just the way it is. ... I won't have to worry about Lynnettee or Kaylene. Everything will just be taken care of. It will just be me."
King County Sheriff Steve Strachan said the video, and other evidence found at the fire-damaged home and in the bunker, revealed that Keller was planning the construction of the bunker as far back as 2004.
Investigators had said earlier that Keller's motive was unclear.
He apparently had a doomsday attitude, authorities said, and some relatives called him a survivalist.
At a news conference Thursday afternoon, Strachan detailed how authorities were able to hunt down Keller even though he was hiding underground in the bunker in a remote area of the Cascade foothills about 25 miles east of Seattle.
Clues about Keller's whereabouts came while investigators were processing evidence at his burned home. The fire did not move beyond the kitchen and failed to ignite a pipe bomb in the residence.
"The suspect in this case intended for all this evidence to be burned, and it wasn't," Strachan said.
Authorities found a hard drive with photos. One of the photos, taken by Keller in a wooded area, showed power lines and helped in the search, Strachan said. People in the area also reported seeing Keller's pickup in a section of the woods, helping detectives narrow their search.
Keller was found in the well-camouflaged bunker six days after the slayings. After a standoff, SWAT team members blew a hole in the roof of the hideout with explosives and saw Keller's body.
In the elaborate bunker, which had rooms, multiple layers and a wood stove, authorities found a gun that matched the one used to kill Keller's family. They also found the video diary that was shot by Keller and showed him talking to himself.
The video was "breathtaking in its evil," Strachan said.
"It is a little bit chilling, because it makes you very aware of the fact that he planned to go into the bunker weeks, months, probably years ahead of time and also indicates that he planned to commit the double homicide years ahead of time," Strachan said.
In the video diary, Keller also spoke about what he would do if he were captured by police.
"I do have my escape, and that's death," he said with a laugh. "I can always shoot myself. And I am OK with that."
The victims' family is setting up a scholarship fund in the memory of Lynnettee Keller that may be funded in part by tens of thousands of dollars also found in the bunker.
Keller was believed to be well armed. "We know he in the past has had a number of rifles, scopes and handguns. He purchased some kind of bulletproof vest," said Sgt. Cindi West of the King County Sheriff's Office.