The suspect, identified as a city engineer, reportedly killed 12 people and wounded four others before he was killed.
One officer was hit in the gun battle and saved by his vest.
Cervera said the first call about a shooter at the Municipal Center came in at 4:08 p.m. Two minutes later four officers—two detective supervisors and two K-9 handlers—arrived on scene. The fast response was the result of the location being just two blocks from police headquarters. There are no reports of the K-9 handlers deploying their dogs at the scene.
The officers formed a rapid response team and immediately went into the building, according to Cervera. Once inside they received information from workers as to what the shooter looked like and what he was wearing. When they heard shots on the employee-only second floor, they moved toward the gunfire.
Once the officers arrived on the second floor and spotted the gunman, he opened fire on them. The ensuing gunfight was fluid and fierce in the tight corridors of the city building, according to Cervera, who said, "It was up close and personal."
Eventually the officers backed the gunman into an empty office, where he started firing at them through the door and the walls, police say. Officers returned the fire.