Donald Clark was found guilty Friday of murdering three people in the summer of 2013.
A Butte County jury found Clark guilty of first degree murder in the deaths of Roland Lowe, 15; and Coleen Lowe, 46.
The same jury found him guilty of second degree murder in the death of Richard Jones Jr. who was 17 at the time of the killing.
Donald Clark, 72, was arrested last summer after the bodies were discovered in a burned car on the Skyway in Magalia.
Prosecution and defense attorneys presented their closing arguments Friday. The jury got the case late Friday morning.
Thursday in court, Clark spoke for the first time during the trial. He indicated he was interested in telling his version of events, but on the advice of his attorney he would not testify.
"What I've heard in the last couple of days was a whole bunch of lies," Clark told the judge. "There's only one person who knows the truth in this room and that's me."
"The law is screwed up. I have an uncle who was a jury commissioner in another county for 30 years. He told me what goes on behind the scenes. This is all wrong."
Prosecutors proved Clark shot and killed Richard Jones Jr., 17; Roland Lowe, 15; and Coleen Lowe, 46, during a confrontation at his rural home in June 2013.
The trial started Thursday, May 8 in Butte County Superior Court in Oroville.