Jason Seaman has been named as the 7th grade science teacher at Noblesville West Middle School who tackled the shooter on Friday.
Multiple parents interviewed by IndyStar identified Seaman as the teacher.
"She kept saying, 'I saw my teacher get shot,'" a parent recalled his daughter saying.
The shooting was reported just after 9 a.m. local time at the middle school in Indiana. A seventh grade male student is in custody.
Another seventh-grade Noblesville student told local media her science teacher charged the gunman, after the shooter entered the classroom and fired a shot at a fellow student.
Seaman reportedly tackled the shooter and was able to swat away the weapon.
Seaman is being treated at IU Health Methodist. A student is being treated at Riley Hospital for Children. Both are in critical condition.
Seaman has been a teacher at Noblesville schools since 2014, according to his LinkedIn profile.