Glen Lee Powell, 30, entered the courthouse shortly after 1 p.m. and approached a security checkpoint wearing a backpack. A deputy ordered him to remove the backpack and place it on a conveyer belt, but he instead threw it on the ground and opened fire with a semiautomatic handgun in the lobby in front of at least four others, Pinellas County Sheriff's Sgt. Jim Bordner said.
Deputies B.J. Lyons and Deputy Marvin Glover returned fire, seriously wounding Powell, who later died at a St. Petersburg hospital. Lyons, a 58-year-old firearms instructor, was treated at a hospital for a shoulder wound and released later that day. No one else was injured, Bordner said.
A representative of Powell's family said he was returning divorce papers due at the courthouse Wednesday. Bishop David Scott -- with the Mormon Church in Brandon, where Powell and his family attended -- said the man's parents did not know he had a gun.
''They weren't aware that he was contemplating this,'' Scott said. ``We don't really understand why it happened.''
The gunfight unfolded as court staffers and a handful of others were in the lobby of the courthouse, which has about 70 employees.
The courthouse was closed after the shooting and is expected to resume normal business on Thursday.
Scott said Powell was living with his parents after returning from duty in the Air Force in California.
He said the family had no indication Powell was troubled. ''He wasn't upset about the divorce taking place,'' Scott said.
He said Powell had done a two-year stint as a missionary in Colombia at his own expense before joining the Air Force.
Detectives are still working to determine a motive, Bordner said. He said Powell's wife is safe and had been notified of his death.
Cassandra Grady, 40, and her 15-year-old daughter went to the courthouse Wednesday and saw the man before the shooting. Grady told the St. Petersburg Times the man asked her where he could file a petition, and that she saw a gun handle in his backpack.
'I told my daughter, 'Run for your life.' Then I started running. I was trying to run to warn them. He started shooting. I heard a round of shots: pop-pop-pop, pop-pop-pop.''
