JACKSONVILLE, Fla. (AP) - The suspect in a deadly shooting at a Florida video game tournament was known to barely speak to fellow gamers and sometimes exhibited an erratic playing style, according to other competitors, who were baffled that their virtual sport could lead to bloodshed.

Authorities say 24-year-old David Katz of Baltimore killed two people and wounded nine others before fatally shooting himself Sunday at the "Madden NFL 19" tournament being held at a riverfront mall in Jacksonville.

"It just doesn't make sense why he would do it," gamer Shay Kivlen, 21, of Seattle, said Monday in an interview. "In 'Madden,' you never get so mad at a loss that you would want to do that."

Jacksonville Sheriff Mike Williams has declined to comment on what motivated Katz to open fire inside a gaming bar connected to a pizzeria at The Jacksonville Landing, a collection of restaurants and shops along the St. Johns River. Williams said he used at least one handgun in the attack.

Such tournaments can involve high stakes. The Jacksonville tournament had $5,000 in prize money to divide among the top finalists. Kivlen said some gamers rely on that money to make ends meet.

But Kivlen and other competitors insisted most players take losses in stride and, even with cash on the line, still view it as being just a game.

"No one deserves to die over playing a videogame, you know?" said Derek Jones, 30, who traveled from Santa Fe, New Mexico, to compete in Jacksonville. "We're just out here trying to win some money for our families and stuff."

The game's maker, EA Sports, lists a David Katz as a 2017 championship winner.

Jones said he was sitting on a back patio outside the tournament venue when he heard the gunshots. He jumped a fence and ran, leaving behind his backpack and cellphone.

"You know, I'm glad I lost today," Jones said. "Because if I'd won, I would have been in that game bar right then playing a game and not paying attention. And he could have come, and I'd probably be dead right now."

Jones said he knew Katz by the gamer tags he used online - often "Bread" or "Sliced Bread" - and had played against him but had never spoken to him personally. Kivlen said that even when Katz showed up at in-person competitions, he never seemed to socialize and would brush off attempts at conversation.

"We've always known he was a little off and stuff just because he wasn't social at all," Kivlen said, adding that Katz's odd behavior extended to his game play.

"He would do kind of weird stuff online that other people wouldn't do. He would catch a ball and just start jumping out of bounds and stuff when he could have gotten more yards, just hurting himself. I don't know what he was doing."

Kivlen, who said he had once beaten Katz for a coveted spot in a tournament, heard secondhand from a friend that Katz had been asking where Kivlen had gone shortly before the shooting.

After losing his single-elimination game Sunday, Kivlen said, he left to take a nap at his hotel about 20 minutes before the attack. He was watching a live stream of the tournament online when the gunfire erupted.

A friend hiding in a bathroom at the venue answered his phone. When he said Kivlen may have been a target, Kivlen called police and an officer was sent to his hotel room for about 90 minutes until they received word that the gunman was dead.

Nine other people wounded by the gunfire were all in stable condition Sunday after being taken to hospitals. Two others were injured in the rush to flee the gunfire, Williams said.

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.

On Sunday evening, the FBI searched the suspect's home. Heavily armed agents, some in bulletproof vests, could be seen entering the upscale townhome complex near Baltimore's Inner Harbor. Agency spokesman Dave Fitz confirmed that agents went to the house of the man's father in Baltimore. He declined to release details.

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Associated Press writers Brendon Farrington in Tallahassee, Florida, and Tamara Lush in the Tampa area contributed to this report.

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