While dozens of gamers were attending a Madden NFL 19 video game tournament in Jacksonville, Florida on Sunday (Aug. 26) a gunman opened fire, killing two people and wounding nine others.

That lone gunman has been identified as 24-year-old David Katz, a Maryland resident who was described as a “disgruntled” gamer who had participated in the Madden tournament.

Katz, who has used the names Bread, mrslicedbread, ravenschamp and ravenschamp2012 in Madden competitions, fatally shot himself at the scene.

Here’s what you need to know about David Katz and the shooting:

1The gunman lost in the Madden tournament and “targeted a few people” before fatally shooting himself, according to witnesses, who also said he was acting “weird.”

The mass shooting happened around 1:30 p.m. Sunday at the Jacksonville Landing, where the Madden tournament was being hosted, according to the Jacksonville Sheriff’s Office. The GLHF Gaming Bar inside Chicago Pizza was hosting a satellite tournament for a nationwide EA Sports-sanctioned Madden NFL 19 competition that will culminate in a Las Vegas event with $125,000 on the line. The Jacksonville tournament, which started Saturday, was the first qualifier to be held in the Madden 19 Classic.

A witness told the Los Angeles Times that the shooter, later identified as 24-year-old David Katz, had played in the tournament earlier and lost. Steven “Steveyj” Javaruski, another competitor in the tournament, told the Times that the gunman came back to the event with a gun and “targeted a few people” before fatally shooting himself.

Another witness, Javaris Long, told the Tampa Bay Times that the gunman was “nerdy” and became angry after he lost, so he went to his car, got his gun, came back into the building and “started blasting everybody.” One source told Fox News that Katz “reacted to losing with violence.”

Drini Gjoka, another one of the gamers, who was struck with a bullet, tweeted: “The tourney just got shot up. I’m [leaving] and never coming back. I am literally so lucky. The bullet hit my thumb. Worst day of my life. I will never take anything for granted ever again. Life can be cut short in a second.” Just moments before that, he tweeted: “won my first single elim game 16-9. Off to Round of 32.”

Police said Katz acted alone in the shooting, contrary to initial reports that there may have been another suspect.

The winner of Sunday’s tournament in Jacksonville was set to win $5,000 along with a chance to advance to Las Vegas where the prize pool was over $100,000. Katz was defeated by two players during the two-day Jacksonville tournament, which started with pool play on Saturday and continued with a single elimination bracket on Sunday, a gamer told WJAX-TV.

Dennis “Evil Ken” Alston, one of the gamers who beat Katz, said he tried to shake his hand yesterday after their game, but Katz stared blankly at him without saying anything. Alston, who has more than a decade of experience in the Madden world, said Katz was acting “weird” all weekend, and was wearing the same clothes on Sunday that he had worn the day before.

Alston said he and the other player who beat Katz were not injured in the shooting, but he said he believed Katz seemed to be targeting certain individuals.

2A Madden Twitch live stream recorded the horrific attack; gunshots and screams were heard as two competitors played a game.

Chilling live stream video footage showing the moment the deadly shooting occurred surfaced on social media immediately following the incident.

The tournament was streamed live via Twitch, an online network that attracts tens of millions of visitors who watch footage of other people playing video games. On one twitch live stream video, more than a dozen gunshots can clearly be heard as well as terrified gamers screaming and crying out. The video does not show the shooter.

The video shows two players competing during the Madden tournament. As they talk about a touchdown run by one of the players, a popping sound can be heard. Then several more gunshots and someone screaming can be heard in the footage. “Oh f***, what’d he shoot me with?” one victim yells out in the video. That person’s identity wasn’t clear.

The sound of controllers dropping to the floor can be heard as several more shots continue to right out. Then, people can be heard scrambling to find safety as many others scream. After a few seconds, the shooting starts back up along with the sound of more people screaming.

You can watch the video here [WARNING – DISTURBING CONTENT]:

Fans watching the video reported seeing a red dot on one of the players’ chest right before the shots rang out. It was later confirmed that player’s name was Eli Clayton, known by his gamer handle “Trueboy,” and he was one of the two shooting victims who died.

3Eli “Trueboy” Clayton and Taylor “Spotmeplzzz” Robertson were killed in the shooting. Nine others were injured by gunfire, and two were injured while trying to flee the area.

The shooting sent at least 11 people to area hospitals, some with gunshot wounds, according to WJAX-TV. Nine people were injured by gunfire, and two were injured trying to flee the Jacksonville Landing. Taylor Poindexter, of Chicago, reportedly injured her ankle while escaping.

Three people were treated at Memorial Hospital in Jacksonville, hospital spokesman Pete Mobeg told CNN, and all three were in stable condition. Meanwhile, University of Florida Health said it was treating six patients, with five of them in stable condition and one in serious condition with a gunshot wound to the chest, UF Health said in a statement. Police later said all of the victims were stable.

One victim, 25-year-old Timothy Anselimo of Brooklyn, a popular gamer known as “OLarry,” was shot three times, his mother shared on Twitter shortly after the incident. She asked for prayers for her son.

She also tweeted pictures of her son and his gamer friends who she said survived by the grace of God. She posted a photo of Florida Gov. Rick Scott visiting her son in the hospital as well.

“Devastated,” Anselimo tweeted Monday. “No words. Surgery in the morning. Thanks to all who reached out.”

https://twitter.com/oLARRY2K/status/1033956774825615360

Anselimo is also a member of the Milwaukee Bucks’ NBA 2K video game team.

Another gamer, “DubDotDUBBY,” said on Twitter that a bullet had grazed his head, adding that he was “traumatized and devastated.”

Eli Clayton, known by his gamer handle “Trueboy,” was identified by friends and the Los Angeles Times as one of the victims who died in the horrific shooting.

Clayton was a 22-year-old from Woodland Hills, California. He identified himself as a Madden Pro player in his Instagram bio and was a Jacksonville Jaguars fan.

View this post on Instagram

Still got work to do.

A post shared by Eli Clayton (@truesowavy) on

Clayton also posted about how excited he was to appear on ESPN and how it was a dream since he was 5 years old.

Back in February, he wrote: “Madden has really changed my life and a game that I used to play for fun is now a big part of my life. Just so blessed to have an opportunity like this. Just such a crazy feeling knowing that tons of people log on and see my face on a Madden NFL game. Unreal.”

Clayton tweeted on August 20th that he had originally planned not to attend the Jacksonville event, but changed his mind.

The second victim who died in the horrific shooting was identified as 27-year-old Taylor Robertson of Ballard, West Virginia. He gamed under the name “Spotmeplzzz” and was a fan of the Tennessee Titans.

https://twitter.com/spotmeplzzz/status/962157342480633857

https://twitter.com/spotmeplzzz/status/962010784577437696

On his Twitter account, @spotmeplzzz, Robertson identified himself as a father, husband and a pro Madden player. He wrote in an August 20th tweet: “Excited for some live madden this weekend in Jacksonville. Time to chase that second belt.”

https://twitter.com/spotmeplzzz/status/1031547906107625476

Robertson died exactly three months shy of what would have been his 28th birthday on November 26th. He and Eric “Trueboy” Clayton were Facebook friends.

4David Katz won a Madden tournament in Buffalo, NY in 2017.

David Katz, playing under the username Bread, won the Buffalo Bills Madden Club tournament in February 2017, according to the EA Sports website. He took home $10,000 for winning that event. You can watch video footage from one of the games from that 2017 tournament below:

The EA Sports website says:

“In what some are calling the most exciting moment in all the 2017 NFL Club Series Championships, David ‘Bread’ Katz won with a walk-off victory by completing an unbelievable pass as time expired to be crowned Buffalo Bills Champion. The crowd at 716 Food and Sport in Buffalo, NY was amazed with the clutch execution in the 4th quarter!”

Katz played another game in the Madden Club Series Championship in Burbank, California in April 2017. He lost that quarterfinals game against another player named Misery.

Katz said in the 2017 video that he typically played Madden NFL on PS4. He was at times ranked among the top players in Madden Ultimate Team, however, social media posts from fellow gamers posted before and after the shooting show he had a reputation for cheating and shady play, including intentionally making games “glitchy” to his advantage.

Katz would also post game strategies and tips on YouTube, Twitch, and elsewhere, including a now-defunct website called “The Gamers Lab.”

Disturbing old tweets about suicide on “The Gamers Lab” twitter account from 2017 led many social media users to connect Katz to the site, saying he was the one tweeter, but The Gamers Lab tweeted Sunday that he didn’t operate the account: “Fyi this was not HIS account. I think he may have posted some youtube videos on the madden tips channel years ago. Thoughts and prayers to the victims and the [families]/friends.”

5Police and federal agents swarmed Katz’ family home in Baltimore, Maryland after the shooting.

Police said Katz was a native of Baltimore, Maryland, and may have stayed in a North Florida hotel Saturday night.

Baltimore Police spokesman T.J. Smith told the Baltimore Sun, “we are assisting our partner law enforcement agencies with some information that has led authorities to Baltimore.”

After the shooting, the FBI and Baltimore Police raided his home and interviewed family members, the agencies said on social media.

Neighbors of Katz’ home, where he stayed with his parents in the 1200 block of Harbor Island Walk near Baltimore’s Inner Harbor, said they rarely saw or talked to him.

EA Sports, the game developer of Madden 19, released the following statement immediately after the shooting: “We are aware of an incident at a sanctioned Madden Championship Series competition in Jacksonville,” the company said. “We are working with authorities to gather facts at this stage. This is a horrible incident and our deepest sympathies go out to all involved.”

In a later statement, Electronic Arts, EA Sports’ parent company, called the shooting a “senseless act of violence that we strongly condemn” and said their “most heartfelt sympathies go out to the families of the victims whose lives were taken… and those were injured.” The statement continued: “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.”

6It isn’t clear how Katz was able to sneak a gun into the gaming bar hosting the Madden tournament. A motive was also not known.

Police haven’t commented about how Katz acquired the gun used in the shooting, nor have they revealed how he got into the gaming bar with the gun and whether or not there was any security, including metal detectors and/or guards, at the event.

Police did say, however, that Katz carried out the shooting with a handgun, and a semi-automatic weapon was also found at the scene. Jacksonville Sheriff Mike Williams said at a press conference that they were investigating whether Katz legally owned the weapon he used in the shooting.

Police located Katz’ vehicle near the scene and approached it with caution in case there were any explosives inside, WESH-TV reported. There were no reports of explosives being found in the car, but it wasn’t known whether any other evidence was found inside the vehicle.

Police would not comment about his motive, but Twitter users said Katz was upset about losing two games of Madden earlier in the tournament, and as mentioned earlier in this article, he refused to shake hands with the winner after at least one game.

Earlier Sunday, while Katz was competing in the tournament, a video showed an announcer introducing Katz while his face remained stoic.

“You are not going to see much emotion from our guy Bread,” the announcer said. “David Katz keeps to himself. He’s a man of business. He’s not here for the experience … he’s not here to make friends. He’s all business, he’s focused, and even to get him to open up to talk to you about anything, it’s like pulling teeth…”