“Hero” officers at Texas’ Santa Fe High School cornered its mass shooter within four minutes on Friday, keeping him contained until more officers arrived to help evacuate teachers and students, according to local police. Galveston Co. Sheriff Henry Trochesset offered new details on how police stopped the gunman in last week’s deadly school shooting, in a press conference late Monday. “The heroes from that [Independent School District] engaged this individual in approximately four minutes and stayed engaged with him, keeping him contained and engaged,” Trochesset said, “so the other heroes—that continued to arrive—could evacuate the teachers administrators in the students from this school.” Alleged gunman Dimitrios Pagourtzis, 17, was cornered in a room while 200 police stormed the school. However, Trochesset could not say for certain whether any students were accidentally struck by bullets fired by police, and autopsy results are still to come. Pagourtzis, who has been charged with capital murder in the massacre that left 10 dead and 13 wounded, is being held on suicide watch, the sheriff said.