Lenexa ? Investigators are trying to determine why a Kansas man entered a suburban Kansas City Costco with a handgun and began screaming, prompting an off-duty police officer to fatally shoot him.

Police identified the man shot to death Sunday at a Costco in Lenexa as 58-year-old Ronald Hunt, of Edwardsville. Witnesses and police said he was yelling and threatening customers when Kansas City, Kan., police captain Michael Howell shot him while customers and employees fled.

Howell, who was shopping at the time, has 22 years of law enforcement experience. The police department said Monday Howell fired his weapon after being confronted with a deadly situation.

No one else was injured.

Hunt’s motive and why he was in the store are under investigation. A Johnson County police unit is leading the investigation.