(AP) — Authorities say an autopsy didn’t answer the question of whether a fall or a crime caused the fatal injuries to a 27-year-old Lincoln man.

David Mueller died Sunday afternoon after he was taken off life support. He was found injured north of downtown Lincoln by a passer-by on June 29.

Mueller’s cellphone and wallet were missing, but police have said it’s not certain whether Mueller was robbed or he fell after drinking heavily. Doctors told police they believe Mueller’s head injuries were more severe than what would have resulted from a fall.