David Katz was the Madden 2017 Championship winner.
Marquis Williams and Taylor Poindexter at first thought they heard a balloon popping. When the loud bangs kept coming, the Chicago couple and fellow video gamers attending a Florida tournament recognised them as gunfire and began scrambling for an exit.
As he fled, Williams, 28, said, he could see the back of the gunman's head as the attacker appeared to be walking backward as he fired.
"We didn't see like a face," Poindexter, 26, told reporters a few hours after the attack, standing on crutches after spraining her ankle trying to escape. "We did see him with two hands on a gun, walking back just popping rounds."
The couple said people trampled others in the panic to escape.
They ran to a nearby restaurant, where workers were waving people inside, and hid in a bathroom until police arrived.
The deadly violence stunned gamers competing yesterday in Jacksonville during a Madden NFL 19 video game tournament. Jacksonville Sheriff Mike Williams said the gunman killed two people and shot 11 others before fatally shooting himself.
The competition was held in a gaming bar. Viewers could watch the games online and see the players.
Williams said authorities believe 24-year-old David Katz of Baltimore carried out the attack using at least one handgun. He said final confirmation of the suspect's identity was pending as the FBI in Baltimore aided in the investigation.
The sheriff said Katz was attending the tournament in Florida. The Madden game's maker, EA Sports, lists a David Katz as a 2017 championship winner.
Authorities did not give a motive for the shootings.
"No one deserves to die over playing a videogame, you know," said Madden competitor Derek Jones, 30, of Santa Fe, New Mexico. "We're just out here trying to win some money for our families and stuff."
Nine other people wounded by the gunfire were all in stable condition yesterday after being taken to hospitals, Williams said. He added that two others were injured in the rush to flee the gunfire.
Investigators were looking into an online video that appeared to capture the scene right before the shooting began, Williams said. A red dot that appears to be a laser pointer is visible on the chest of a player seconds before the first of about a dozen gunshots rings out.
One Twitter user, Drini Gjoka, said he was taking part in the tournament and was shot in the thumb. "Worst day of my life," Gjoka wrote on Twitter. "I will never take anything for granted ever again. Life can be cut short in a second."
The Jacksonville sheriff's office said the FBI was assisting them in Baltimore, and the Baltimore Sun reported that agents were at a home in South Baltimore in connection with the investigation.
The latest rampage occurred amid a debate over United States gun laws that was given fresh impetus by the massacre in February of 17 people at Stoneman Douglas High School in Parkland, Florida. Two years ago a gunman killed 49 people at the Pulse nightclub in Orlando.
TOURNAMENT TRAGEDY
• A contestant atavideo game tournament in Jacksonville shot and killed two people and injured 11. He then shot and killed himself.
• The shooter:David Katz Aged 24, of Baltimore. In town for the competition, which was being streamed online.
• Katz had been competing in the tournament and lost, then apparently targeted other players before killing himself.
• The tournament: The Madden 19 NFL Classic, a regional qualifier. The top two finishers go on to compete at the Madden Classic main event in Las Vegas in October.