David Katz has been identified as the gunman who opened fire Sunday during a Madden NFL 19 video game tournament in Jacksonville, Florida, killing two people and wounding nine others, authorities said at a press conference.

The 24-year-old Katz, a Maryland resident who fatally shot himself at the scene, was described as a “disgruntled” gamer who had participated in the Madden tournament, sources told Fox News’ Rick Leventhal. Katz has used the names Bread, mrslicedbread, ravenschamp and ravens2012champ in Madden competitions.

Katz is a former University of Maryland student, though he’s not currently enrolled, UMD president Wallace D. Loh confirmed.

The mass shooting happened about 1:30 p.m. Sunday at The Jacksonville Landing, the Jacksonville Sheriff’s Office said on Twitter. 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.

The event was being shown on Twitch, a live streaming video platform, and that live stream captured the moments that gun shots rang out. You can watch that disturbing video here. Police initially said four people were killed, but later said three were dead including the shooter.

The two gamers killed in the shooting have been identified as Eli “TrueBoy” Clayton and Taylor “SpotMePlzzz” Robertson, say they have not been heard from since the shooting and they are feared dead. TrueBoy was playing on the live stream when the shots rang out.

This story is still developing and will be updated with more information about David Katz as it is available. Here is what we know so far about him and the shooting:

1. The Suspect Lost in the Madden Tournament & ‘Targeted a Few People’ Before Shooting Himself, Witnesses Say

A witness told the Los Angeles Times that the shooter, identified as David Katz, had played in the tournament earlier and lost. Steven “Steveyj” Javaruski, who was another competitor in the tournament, told the newspaper 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 suspect was “nerdy” and got mad because he lost, so he went to his car, got his gun, came back and “started blasting everybody.”

Drini Gjoka, another one of the gamers, tweeted, “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.”

Jacksonville Sheriff's Office: Multiple Fatalities In Florida Shooting | MSNBCJacksonville Sheriff's office says multiple people have been killed in Jacksonville mass shooting, and many more victims have been taken to hospitals. » Subscribe to MSNBC: http://on.msnbc.com/SubscribeTomsnbc About: MSNBC is the premier destination for in-depth analysis of daily headlines, insightful political commentary and informed perspectives. Reaching more than 95 million households worldwide, MSNBC offers a… 2018-08-26T19:18:10.000Z

Police said the suspect was the lone shooter. There had been initial reports that there may have been another suspect but that was quickly ruled out. Police said Katz was the only suspect and after shooting a dozen people, he turned the gun on himself.

A source told Fox News that Katz “reacted to losing with violence.”

The winner of the Jacksonville tournament was set to win $5,000 and a chance to advance to Las Vegas where the prize pool was over $100,000. Two players defeated Katz 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.

“He says he tried shake alleged shooter’s hand yesterday after their game, alleged shooter stared blankly. Says shooter was acting ‘weird’ and wearing same clothes as yesterday,” WJAX reporter Ryan Nelson tweeted. He said the two players who beat Katz were not injured during the shooting, but he said Katz did seem to be targeting people.

2. Gunshots & Screams Were Heard on the Madden Twitch Stream as Two Competitors Played a Game

We are above scene at Jacksonville Landing. Largest police presence I’ve seen. 15 shot. At least 4 dead, according to my sources. pic.twitter.com/QqErG7PTiB — Vic Micolucci WJXT (@WJXTvic) August 26, 2018

On a Twitch live stream video, more than a dozen shots can be heard as well as people screaming and crying out.

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 are heard on the video. The sound of controllers dropping to the floor can be heard as several shots continue to ring out. People can be heard scrambling and more screams can be heard. After a few seconds the shooting starts again along with the sound of more people screaming.

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

Shooting at the Madden NFL 19 Tournament Whilst Live On Twitch In JacksonvilleShooting at the Madden NFL 19 Tournament Whilst Live On Twitch #Madden #Twitch #Shooting 2018-08-26T17:59:48.000Z

The video also appears to show a red dot on the shoulder of one of the players, but it is not clear if that is connected to the shooting.

The tournament in Jacksonville was the first of several satellite events planned by EA Sports as part of the Madden NFL 19 Classic tournament, a nationwide event bringing together the top gamers in the world. The tournament is set to conclude with winners of the satellites playing in Las Vegas. The Jacksonville satellite tournament attracted some of the top Madden players from the southeastern region of the country and the games were being streamed live on Twitch.

Watch: Witness describes the scene after the Jacksonville mass shooting: "It's scary" pic.twitter.com/EPo7EzUpdd — MSNBC (@MSNBC) August 26, 2018

The shooting sent at least 11 people to local hospitals, some with gunshot wounds and according to WJAX-TV.

Three people were being treated at Memorial Hospital in Jacksonville, Pete Mobeg, a hospital spokesman, told CNN. All three are in stable condition, Moberg told CNN. University of Florida Health said it is treating six patients. Five of those victims are in stable condition, while one is in serious condition with a gunshot wound to the chest, UF Health said in a statement. But police later said all the victims are in stable condition.

My sons Bucks gaming book bag with his blood from being shot pic.twitter.com/1oJSocbf3h — Sujeil (@olarrysmom) August 27, 2018

One victim, Timothy Anselimo of Brooklyn, a popular gamer called OLarry, was shot three times, his mother posted on Twitter shortly after the rampage. She asked for prayers for her son.

The governor of Florida with my son @oLARRY2K pic.twitter.com/nP0VCLUyYY — Sujeil (@olarrysmom) August 27, 2018

By 8 p.m. Sunday night, she tweeted pictures of her son and gamer friends who she said survived by the grace of God. She also posted a photo of Florida Gov. Rick Scott visiting her son in the hospital.

3. Katz, Who Won a Madden Club Championship Event in Buffalo in 2017, Was a College Student

David Katz, playing using the nickname Bread, won the Buffalo Bills Madden Club tournament in February 2017, according to the EA Sports website. He won $10,000 during that event. You can watch one of the games from that 2017 tournament below:

Madden 17 | Cino vs Bread | Bills Challengerfollow me on social media Snapchat: Trinidadx Instagram: http://www.instagram.com/Trinidad_ Twitter: http://www.twitter.com/GG_Trinidad -~-~~-~~~-~~-~- Please watch: "How Good Was Prime Darrelle Revis ?" https://www.youtube.com/watch?v=xnxI41ae53A -~-~~-~~~-~~-~- 2017-03-06T00:25:16.000Z

“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 EA Sports website says. “The crowd at 716 Food and Sport in Buffalo, NY was amazed with the clutch execution in the 4th quarter!”

Madden 17 | Misery (Steelers) Vs. Bread (Bills) | Madden Club Series ChampionshipBusiness Email – Comptonxxx187@gmail.com Down For A Wager Add me and Message Xbox Gamertag – Compton x 187 follow me on social media Snapchat: Trinidadx Instagram: http://www.instagram.com/Trinidad_ Twitter: http://www.twitter.com/GG_Trinidad "NFL Highlights, Must watch, Hall Of Fame, Super Bowl, MUT, Madden NFL 17, NFL 2K17, EASPORTS", 2kSPORTS, Giveaways, "Scammers Caught", Primetime, Beastmode, The G.O.A.T, NFL Top… 2017-04-27T21:34:14.000Z

Katz played another game in the Madden Club Series Championship later in 2017 after advancing through winning the Bills tournament. He lost that quarterfinals game against Misery. It was played in Burbank, California, on April 15.

Katz says in the 2017 video that he typically played on PS4. He was at times ranked among the top players in Madden Ultimate Team, but social media posts from fellow gamers posted both 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 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 on social media to connect Katz to the site, saying he was the one tweeting. But “The Gamers Lab” posted Sunday denying that he operated 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.”

Katz was also a student at the University of Maryland, though was not enrolled for the fall 2018 semester. It’s not yet clear what he was studying at the university.

I have been informed that the alleged gunman in yesterday’s tragedy in Jacksonville attended UMD previously but was not enrolled this semester. Our community grieves for the friends & families of the victims. My statement: pic.twitter.com/xcn5hE3KTp — Wallace D. Loh (@presidentloh) August 27, 2018

UMD president Loh tweeted, “I have been informed that the alleged gunman in yesterday’s tragedy in Jacksonville attended UMD previously but was not enrolled this semester. Our community grieves for the friends & families of the victims.” Loh encouraged anyone with information about Katz that may be relevant to contact authorities.

4. Court Records Show Katz, Who Bought the Guns From a Licensed Dealer in August, Had ‘Significant Medical Problems & Needs’ & Was Hospitalized for Mental Illness

Mass shooting in Jacksonville, FloridaPolice in Jacksonville, Florida, say they're responding to a mass shooting at the Jacksonville Landing marketplace in the city's downtown area. The Jacksonville Sheriff's Office is warning residents to avoid the area. 2018-08-26T18:57:06.000Z

Police have not commented about how the gunman acquired the gun used in the shooting. It is also not clear how the shooter got into the gaming bar with the gun and whether there was any security, including metal detectors or guards, at the event.

He was armed with two semi-automatic handguns during the shooting, police said. According to authorities, he had a a .45 caliber and a 9mm along with extra ammo. One of the guns was equipped with an aftermarket laser sight, police said. Jacksonville Sheriff’s Department Chief Mike Williams said only one of the guns was used by Katz. According to the ATF, both of the guns were bought within the month of August in Baltimore from a licensed dealer.

BREAKING: Law enforcement official just told us they have found the car belonging to the suspect in the mass shooting in Jacksonville and they are approaching it with caution in case there are explosives. A bomb detecting robot has been brought in. — Amanda Ober (@AmandaOberWESH) August 26, 2018

Police found the shooter’s vehicle near the scene and were approaching it with caution in case there were explosives inside, WESH-TV reports. There are no reports of explosives being found in the car, but it is not yet known if any other evidence was located inside the vehicle.

Police would not comment about his motive. They said it is believed he had stayed in the Jacksonville area Saturday night, but they are looking for more information about when he came to the city. By Sunday night, the JSO confirmed earlier reports; investigators had found Katz’ car but were left with more questions than answers.

Single suspect is a white male. Pending confirmation, believed the suspect is a 24-year-old, David Katz from Baltimore, MD. FBI is assisting in Baltimore, MD. for Jacksonville Florida PD. pic.twitter.com/j7gVXpBgWc — Joshua Jered Rodriguez (@Joshuajered) August 27, 2018

“We have located and impounded the suspect’s vehicle and a search is pending. We believe he stayed somewhere locally last night. If anyone has information about where he stayed, please contact 904-630-0500 or JSOCrimeTips@Jaxsheriff.org”

In court records obtained by Heavy, his parents, mother Elizabeth, a toxicologist who worked at the Food & Drug Administration and now works at the Health & Human Services department earning around $107,000 a year, and Richard, a engineer employed by NASA earning around $146,000 annually, divorced in 2007. At the time, their two sons, Brandon now 28, and David, 26, both had “significant medical problems and needs,” court records show.

The reason their health problems were made known in court records had to do with a dispute between their parents on health insurance coverage. Not to get in the weeds with the incongruous court decision, suffice to say that some of the sons’ medical bills were “extraordinary.” It’s noted that at the time their mother sought to have the divorce decree modified and have insurance coverage amended, both Brandon and David were adults and considered emancipated, the records read, but were still, documents show, described as children under their parent’s care.

According to additional court records from the divorce obtained by The Associated Press, Katz was twice hospitalized in psychiatric facilities as a teenager and was prescribed anti-psychotic and anti-depressant medications. “The records show Katz’s parents disagreed deeply on how to care for their troubled son. Katz’s father claimed his estranged wife was exaggerating symptoms of mental illness as part of the couple’s long-running and acrimonious custody battle,” the AP reports.

5. Police & Federal Agents Were at a Home in South Baltimore Believed to be Connected to Katz

According to the Jacksonville Sheriff’s Office, Katz is from Baltimore. Sheriff Mike Williams said late Sunday that the FBI in Baltimore is assisting his office with its investigation.

HAPPENING NOW: FBI and ATF are at a home in Federal Hill, South Baltimore, which may be associated with the Jacksonville, FL mass shooting. #WJZ pic.twitter.com/bsNozePUEW — Devin Bartolotta (@WJZDevin) August 26, 2018

According to the Baltimore Sun, police were at a home in South Baltimore Sunday evening as part of the investigation into the Jacksonville shooting.

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

BREAKING: The Jacksonville Sheriff's Office said they believe the video game tournament shooter is 24-year-old David Katz of Baltimore. ATF is in a waterfront neighborhood in South Baltimore investigating. @WMAR2News pic.twitter.com/FK6Nqojq7l — Abby Isaacs WMAR (@AbbyIsaacsNews) August 26, 2018

Baltimore TV news station WMAR located what it believes is Katz’ parent’s home, or at least according to property records, is the home owned by Richard Katz. ATF agents can be seen parked outside the property on Harbor Island Walk, a very tony and upscale Baltimore harbor neighborhood.

Meanwhile, the investigation into the shooting is ongoing with the JSO, FBI, Florida Department of Law Enforcement and the ATF involved.

“I’ve spoken to @JSOPIO Mike Williams to offer any state resources he may need. FDLE is currently responding, and I have spoken to FDLE Commissioner Rick Swearingen regarding the shooting in Jacksonville. We will continue to receive updates from law enforcement,” Gov. Scott tweeted.

Scott added, “Just spoke with @POTUS regarding the shooting at the Jacksonville Landing. He offered any federal resources needed to respond. FDLE and the Florida Highway Patrol are currently assisting local law enforcement.”

Mass shooting scene in downtown Jacksonville. pic.twitter.com/DR6MAoCZH2 — Vic Micolucci WJXT (@WJXTvic) August 26, 2018

EA Sports, which makes the Madden NFL 19 game, tweeted, “We are aware of an incident at a sanctioned Madden Championship Series competition in Jacksonville. We are working with authorities to gather facts at this stage. This is a horrible situation, and our deepest sympathies go out to all involved.”