-- A New York man who is already in prison for murdering his son is now facing new murder charges in California for the death of his first wife.
Karl Karlsen, 54, who is currently serving 15 years to life at a prison in upstate New York for killing his son Levi Karlsen, was charged today with first-degree murder in the 1991 death of his wife, Christina Karlsen, who is also Levi's mother. She died on Jan. 1, 1991 in a fire at their family home in California. Her death had been initially ruled an accident.
Barbara Yook, the district attorney for Calaveras County, charged Karl Karlsen with one count of murder during the commission of arson. Yook declined to comment on the case when reached by ABC News today.
Unlike his case in New York state, if convicted in this new case in California, Karlsen could face the death penalty. A court date has yet to be announced.
Levi Karlsen, 23, was crushed to death in 2008 when the truck he was working on slipped off a jack and landed on top of him. His death was initially ruled an accident, but prosecutors later claimed Karl Karlsen killed him so he could collect a $700,000 life insurance payout.
During his trial last year, Karlsen admitted he rigged the jack so the truck would fall on Levi, and pleaded guilty to second-degree murder in November 2013.
New York authorities started investigating Karlsen after his second wife, Cindy Karlsen, came forward last year and told police of her suspicions of Karlsen's involvement with Levi's death. Authorities in California then opened an investigation into Christina Karlsen's death. That investigation was concluded this week.
Karl Karlsen collected a $200,000 life insurance payout after his first wife died, but hadn't been charged in anything related to her death until now.
Christina and Karl Karlsen’s daughter Erin told ABC News' "20/20" in a 2013 exclusive interview that she was always suspicious of her father.
"We knew what he had done to our mother, and I knew what he did to my brother," Erin said at the time.
Erin was 6 years old when she, Levi and their sister Katie escaped from the house fire that killed their mother. According to Erin, their father helped his children get outside safely, and then they stood and watched the house burn.
"I didn't understand that my mother was behind that wall dying," Erin told "20/20" at the time, adding that her father "didn't make an effort to save her. He just stood there."
A week after the fire, Karl Karlsen and his three children left California for upstate New York to be near his family, and he eventually remarried.
As they got older, Erin said she and Levi started to wonder if their father had been responsible for their mother's death. However, when they confronted him about it, Erin said, "his biggest concern was that he wondered what the community would think of his own children accusing him of murdering their mother."
ABC's Lauren Effron contributed to this report