Peter Keller, 41, who shot his wife, Lynnettee, and their 18-year-old daughter, Kaylene, in April, set fire in their Seattle-area home and killed himself days later, left behind the video diary in which he spoke about killing his family, CNN reported.
The video, released Thursday, was found in an underground bunker where Keller's body was found six days after the slayings. After a standoff, SWAT team members blew a hole in the roof of the bunker with explosives and saw Keller's body. The Seattle Times said he had shot himself.
King County Sheriff Steve Strachan said of the video: "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."
The video shows Keller walking in the woods.
"A while ago I used to sit here and think, you know, this whole thing is crazy," he said. "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."
Keller's motive was unclear, investigators said.
Notable deaths of 2014 [PHOTOS]