Jacksonville Landing employees put signs out in front of the facility announcing that it would be closed for the day and would reopen Tuesday following Sunday's mass shooting.

JACKSONVILLE, Fla. — A California man who played video games to earn money for college and a West Virginian whose e-sports winnings helped support his young family were slain at a Florida tournament where a gunman specifically targeted fellow gamers, authorities said Monday.

David Katz, 24, of Baltimore fatally shot himself after killing the two men and wounding 10 others Sunday inside a pizzeria and bar that were hosting a “Madden NFL 19” tournament. Katz was among about 130 gamers attending the competition at a mall in Jacksonville.

Katz carried two handguns, including one equipped with a laser sight, into the tournament venue but only fired one of them, Jacksonville Sheriff Mike Williams told a news conference Monday. He said surveillance video revealed Katz was the only shooter, but his motive remains unknown.

“The suspect clearly targeted other gamers who were in the back room” of the pizzeria, Williams said. “The suspect walked past patrons who were in other parts of the business and focused his attention on the gamers.”

Investigators determined Katz bought both guns in Baltimore within the past month. But Williams said there’s no indication he planned the shooting before Sunday.

The sheriff had previously said nine people were wounded by gunfire, but told reporters Monday the total was 10. All of them, he said, were expected to recover.

The sheriff’s office identified the dead as 22-year-old Elijah Clayton of Woodland Hills, Calif., and 28-year-old Taylor Robertson of Giles, W. Va.

Clayton’s parents and other relatives gathered outside police headquarters Monday in Jacksonville to give a brief statement. A cousin, Brandi Pettijohn, said the family was “devastated by yet another senseless act of gun violence.” She said Clayton was a good, peaceful man who never had a fistfight.

“He loved football, and out of all the video games he could play, he settled on and mastered ‘Madden,’” Pettijohn said. “He made a good living gaming, and he saved his earnings so he could afford to go to college to continue his education.”

Robertson, who used the gamer tag “Spotmeplzzz,” won the Madden Classic tournament in 2016. In a YouTube interview published by EA Sports, Robertson said he had played Madden NFL since he was 10 and started playing competitively a few years ago.

“It’s certainly possible for any player to do this,” Robertson said in the video. “You’ve just got to put in the time. You’ve got to grind. You’ve got to play a lot of games and just working on getting better.”

Fellow gamers described Robertson as a family man dedicated to his wife and children.

Gamer Derek Jones, who lost to Robertson in the 2016 tournament, said his onetime rival was “one of the nicest people I ever met.”

“There’s no way that guy did anything to deserve to get shot,” said Jones, who traveled to the Florida tournament from Santa Fe, N.M. “He’s got a family at home, and he just came out here to try to win some money for this family.”

Gamer Shay Kivlen of Seattle said he met Clayton, whose gamer tag was Trueboy, about five years ago. They bonded because both of them played games on a PlayStation 4 — which put them at odds with many gamers who prefer Microsoft’s Xbox.

The two friends would chat daily online and see each other about six times a year at tournaments.