IOWA CITY, Iowa -- The family of a deceased Luther College student from Ghana is criticizing the investigation that ruled his death accidental due to hypothermia.

Family members of Nabby Baffour-Awuah said they believe the 24-year-old from Ghana was assaulted and/or chased before his death on Jan. 1 on the campus in Decorah. They said a 911 call in which Baffour-Awuah warned "he's going to kill me" and other details suggest the evidence of foul play is strong.

Police announced in February they believed Baffour-Awuah died of hypothermia in freezing temperatures after he was locked out of his dormitory following a night of drinking at an off-campus party.

His family said in a statement that characterization "was an insult to the known facts, the memory of Nabby, and to this family."