(ABC News) -- When Karl Karlsen found his son, Levi, crushed to death under a jacked pickup truck he had been repairing, he was "distraught" and told police he tried to save his 23-year-old son.
Four years later, what seemed like an accidental death is now suspected of being a ruse perpetrated by Karlsen to collect his son's life insurance policy, prompting authorities to also take a closer look at a New Year's Day 1991 house fire in California that killed Karlsen's first wife, Christina.
Karlsen, 52, was arrested Friday on a second degree murder charge in the death of his son.
"We will be talking with investigators in California in the coming days as there are certain events surrounding the death of Karlsen's first wife that cause us concern," Seneca County Sheriff Jack Stenberg said in a statement.
The case shifted from accidental to a murder investigation in March of this year when authorities discovered Karlsen had taken out a "substantial" life insurance policy on his son days before he died, Stenberg said.
Other evidence also pointed to the fact that Levi''s death was not accidental, Stenberg said, however he declined to discuss specifics during the investigation.
"There were no indications of foul play and from all signs this appeared to be a very tragic accident," Stenberg said, regarding the scene on Nov. 20, 2008.
A distraught Karlsen told authorities he had left at noon to attend a family gathering and returned to his Romulus, N.Y., home four hours later to find his son pinned motionless under the truck.
While he worked to rescue his son, Karlsen's new wife, Cindy, called 911. Levi Karlsen, who was the father of two children, was pronounced dead on arrival at Geneva General Hospital.
"To think that a father could cause a vehicle to fall off a jack crushing his son and then leave for four hours knowing all the time that his son was pinned under the truck apparently dead is unconscionable," Stenberg said. "Then, to put on an act for arriving first responders was part of a well-planned event staged by Karl Karlsen."
Art Alexander, whose daughter was married to Karlsen and perished in the 1991 fire, told the Syracuse Post-Standard he always had suspicions about his former son-in-law but kept quiet, so he wouldn't be restricted from seeing his grandchildren.
After Christina's death, Alexander said Karlsen and his two children immediately moved to New York, where he said his former son-in-law purchased a farm with $200,000 of insurance money he collected from his wife's life insurance plan.
"Just to keep it bottled up — it was the hardest thing I ever did in my life," he said.
Karlsen was arraigned and remains in Seneca County Jail without bond. His next court appearance, a felony hearing, is scheduled for this Thursday.
Karlsen has not yet entered a plea.