The man who police say killed two people at a Jacksonville, Fl. video game tournament on Sunday — before taking his own life — was a gamer who was eliminated from the competition earlier in the day, according to American media reports.
The Jacksonville Sheriff’s Office said David Katz, 24, killed two people before turning his gun on himself. Nine people were injured in the shooting.
The murder-suicide occurred during a Madden NFL 19 video game tournament in a restaurant at the Jacksonville Landing, a waterfront retail and entertainment complex in downtown Jacksonville.
The Los Angeles Times reported earlier that the shooter was a gamer who was competing in the popular football video game tournament and lost. Citing messages from another player in the room, the Times said the gunman appeared to target multiple victims before killing himself.
One woman told ABC that the shooter had gotten into an argument with another gamer, after which he went and stood at the back of the room. She said he began firing shortly thereafter.
WATCH: Full coverage of the shooting in Jacksonville, Fl.
A witness told Fox News that the shooter “was a gamer, for sure,” and said there were “multiple guys who were upset” at being knocked out of the competition, a regional qualifying tournament for the national Madden NFL Championship.
A man who said he defeated Katz in the tournament told CBS affiliate WJAX that Katz was a “well-known competitor,” but that he kept to himself and didn’t interact with anyone else at the weekend event.
“He was weird all weekend, I mean he had shades on, he just — he didn’t speak to anybody,” the man said. “Even after we played, I beat him, I went to shake his hand and tell him ‘good game’ and he just looked at me. He didn’t say anything.”
WATCH: Madden competitor says he beat suspected shooter in video game
Madden competitor Derek Jones, 30, said he was sitting in a back patio outside the tournament venue when he heard the gunshots.
Jones said he knew Katz by the gamer tags he used online — often “Bread” or “Sliced Bread” — and had played against him online but had never spoken to him personally.
Police confirmed that Katz was in the restaurant for the tournament, but didn’t comment on his motive or the events leading up to the shooting.
The maker of the Madden NFL video games, EA Sports, lists a David Katz as the winner of a 2017 championship among gamers representing NFL team The Buffalo Bills.
A February 2017 tweet from the Bills’ official Twitter account shows a David Katz posing with his winner’s jersey.
EA Sports condemned what it termed a “senseless act of violence,” and said it was supporting authorities in their investigation.
“Our most heartfelt sympathies go out to the families of the victims whose lives were taken today and those who were injured,” the company said in a statement. “All of us at Electronic Arts are devastated by this horrific event, and we also join the community in thanking the first responders who were quickly on the scene.
“Our focus right now is on those affected, and supporting law enforcement as they continue their investigation into this crime.”
— With files from Reuters and the Associated Press