Omaha police say the shotgun used by a man killed in a New Year's Day standoff was unloaded, but he posed an imminent threat by using his 3-year-old son as a human shield.

Police chief Todd Schmaderer said Wednesday that 31-year-old Tyree Bell was holding his twin children inside the north Omaha home when officers responded to a domestic disturbance call.

Schmaderer says Bell repeatedly made threatening and suicidal comments. Bell eventually released the couple's daughter, but Schmaderer says Bell held his son in front of him while pointing both a pellet gun and shotgun at officers.

Four officers who fired their guns are on administrative leave, pending an investigation. They were identified as 31-year-old Douglas Arrick, 36-year-old Carl Hanson, 29-year-old Chithauta Hester and 35-year-old Alan Peatrowsky.