A Emery County man who shot and killed his mother two years ago because he thought she was a demon, and moments later fatally shot his brother, has been sentenced to prison for up to life.
Seth Gordon Peterson, 26, was convicted in December by a 7th District Court jury of second-degree felony manslaughter in the November 2016 death of 45-year-old Susan Peterson — allegedly while the son was experiencing a methamphetamine-induced psychosis and believed his mother was a demon.
But the jury did not find Seth Peterson was intoxicated by drugs — or suffering from any hallucinations — about 30 seconds later, when he shot his brother, 23-year-old James Peterson.