A 24-year-old man fatally shot two men and injured 10 others before turning the gun on himself Sunday during a video game tournament at a Jacksonville pizzeria, investigators said.
Deputies said three people, including the gunman, died in the shooting, and 10 others were wounded. Another person was injured while running away from the gunfire.
The shooting happened at The Jacksonville Landing -- an open-air mall on the St. Johns River. Officials said about 150 people were in the pizzeria at the time of the shooting.
Jacksonville authorities identified David Katz, of Baltimore, Maryland, as the gunman. He killed himself during the tournament, during which competitors from around the country were playing "Madden NFL 19."
On Monday afternoon, deputies identified Elijah Clayton, 22, of Woodland Hills, California, and Taylor Robertson, 28, of Giles, West Virginia, as the men whom Katz fatally shot.
JACKSONVILLE, Fla. — Read: Central Florida reacts to the mass shooting in Jacksonville
Deputies have not confirmed a motive for the shooting, but they said it appears that Katz targeted his victims. Witnesses told Channel 9 that Katz was upset that he had lost a match earlier in the day.
"There's a lot of conversation about that, but we are yet to have a concrete motive," Jacksonville Sheriff Mike Williams said.
Survivor Dennis Alston said Katz had behaved oddly Sunday.
"He was weird all weekend," he said. "He had shades on. He didn't speak to anybody. 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."
Read: Reaction to video game tournament deadly gunfire
Out of the 11 injured, 10 were treated for gunshot wounds. The other injury happened when the victim fled the scene, authorities said.
A spokesman for UF Health Jacksonville said six patients were treated. One is in serious condition and the other five are in good condition.
Read: Jacksonville shooting victim's dad tells of 3 bullets, awful fear
Memorial Health also confirmed they have three victims from the shooting. All of their patients are described as being stable.
Clayton's relatives said Monday that he was in town for the tournament. They said he loved football and began playing video games professionally to help pay for college. Relatives said Clayton knew Katz through the gaming community.
"Elijah's family wants you to know he was a good man," relative Brandi Pettijohn said. "He did not believe in violence. He never even had a fist fight."
Katz was also in town for the tournament, according to the Sheriff's Office.
Deputies said Katz legally purchased two guns from a licensed dealer in Maryland last month and he had extra ammunition with him. One of the gun's had a laser sight on it, officials said.
Bureau of Alcohol, Tobacco, Firearms and Explosives agents said they searched Katz's home Sunday.
The Federal Bureau of Investigation said his parents have fully cooperated with investigators so far.
The Sheriff's Office said Katz used one handgun during the shooting. He stayed somewhere in the area on Saturday night, but authorities said they are still trying to find out where he stayed.
Court records said Katz was hospitalized in the past for mental illness.
Divorce filings from his parents said he was admitted twice as a teenager to psychiatric facilities and was prescribed anti-psychotic medication as well as anti-depressants.
The records also said that Katz's parents disagreed on how to care for their son's mental issues.
Watch: Jacksonville Sheriff gives update on mass shooting
#JSO says people are still hiding at the Jacksonville Landing. They're asking they call 911 so officers can come get you @ActionNewsJax pic.twitter.com/u95FelUgkC
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