BANCROFT, Neb. (AP) — Prosecutors have filed a murder charge against a 48-year-old man whose son faces the same charge in a northeast Nebraska slaying.

Jody Olson and his son, Derek, are charged with second-degree murder, arson and related crimes. They’re accused of killing 64-year-old Ernest Warnock, whose body was found March 11 in the rubble of his home north of Bancroft. Investigators have determined that he’d been stabbed to death during an altercation before the fire began.

Court records say Jody Olson originally was charged only with being an accessory to a felony. It’s unclear what led prosecutors to file the additional charges. Olson’s attorney and the prosecuting attorney didn’t immediately return calls Friday from The Associated Press.