The gunman who shot dead two people at a Florida video tournament Sunday was a disgruntled gamer who had played there and lost, a competitor said.

The shooter “targeted a few people” and shot them before killing himself, gamer Steven “Steveyj” Javaruski told the Los Angeles Times in a direct message on Twitter.

The gunman killed two or three people “that I saw,” Javaruski added.

The shooting horror was partially captured on a live stream of the Madden video-game competition that was broadcast from the conference.