Curtis Reeves, 71, shot Chad Oulson, 43, during an argument in Wesley Chapel, Florida, about Oulson's texting during the previews of the movie "Lone Survivor."
Reeves and his wife were sitting behind Chad Oulson and his wife, Nichole, and complained about their text messaging. Authorities said Chad Oulson was texting his young daughter's babysitter.
Reeves got up and left the theater to tell management, and the argument escalated when he returned. Witnesses said popcorn was thrown, and then Reeves pulled out a .380 semiautomatic handgun and fired, striking Nichole Oulson's hand as she tried to block the shot, which struck Chad in the chest.
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.
Both victims were taken by air to Tampa General Hospital, where Chad Oulson was pronounced dead. His wife was treated for injuries.
Reeves is charged with second-degree murder and is being held without bond. He did not enter a plea.
A judge presiding over Reeves' first court appearance Tuesday said the evidence of his guilt was "significant." The prosecutor in the case told the judge that investigators had received a call from another concerned moviegoer who said Reeves had once followed her to the bathroom over her texting.
Experts on Florida law say that Reeves could invoke "Stand Your Ground" as a defense of the shooting, but would have to convince a judge or jury that he reasonably feared for his life and felt he could not retreat, which they said would be a challenge.
"This could be a situation where Stand Your Ground is used. The defendant's statements to police is information that could be used to establish self-defense," said Kenneth B. Nunn, professor of law of the University of Florida's Levin College of Law. "But part of self defense requires you to retreat if you can do so in complete safety."
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.
ABC News contributed to this report.