LINCOLN, Neb. (AP) — Nebraska authorities say a 46-year-old engineer stabbed to death at his daughter’s birthday party was killed by his father-in-law.

Seventy-seven-year-old Bayapa Lingala was charged Wednesday with second degree murder and use of a weapon to commit a felony. Lincoln Police say they arrived at an area residence Tuesday night and found 46-year-old Sujay Nooka with a 1.5-inch stab wound to his upper chest. He was taken to an area hospital where he was pronounced dead.

Authorities say they found Lingala in the basement with an 8-inch knife covered in blood.

A police spokeswoman says investigators are trying to determine what prompted the stabbing.

It’s unclear whether Lingala has an attorney. The case isn’t listed yet in online court records.