"Somebody throws popcorn. I'm not sure who threw the popcorn," Charles Cummings, who was at the movies as a birthday treat, told the Associated Press. "And then bang, he was shot."
"I can't believe people would bring a pistol, a gun, to a movie," Cummings said. "I can't believe they would argue and fight and shoot one another over popcorn. Over a cellphone."
Oulson's wife is recovering from her hand wound, authorities said.
"She's a wreck. I mean she just lost her husband, the father of her little girl," family friend Joseph Trapani told ABC News affiliate WFTS-TV in Tampa.
An off-duty Sumter County Sheriff's deputy who was in the theater quickly subdued the alleged gunman and took possession of his weapon, police said. The off-duty deputy, who held Reeves until arresting officers arrived, was not immediately identified.
Tampa police identified Reeves as a former captain who retired 20 years ago after helping create the department's Tactical Response Team. Busch Gardens theme park confirmed to ABC News that Reeves was once its director of security.
Police said the alleged shooter and victims did not appear to know one another.