Updated

South Carolina authorities say a gunman killed two security guards and his stepfather and wounded a police officer before fatally shooting himself in the head.

Greenville County Sheriff Steve Loftis says 23-year-old Evan Casey Bennett shot the security guards last Thursday night, but wasn't immediately identified and captured. Interim Greenville Police Chief Mike Gambrell says Bennett killed his stepfather on Monday before heading over to the Greenville County Law Enforcement Center, where he shot out windows and fired on the officer before turning the gun on himself.

The police chief said Bennett was wearing a tactical vest and camouflage pants and carrying a knife when he arrived at the center, which houses the Greenville Police Department and the local sheriff's office.

Gambrell said Bennett killed his stepfather following an argument. Loftis described the other shootings as a "senseless thrill killing."