Officer Mark Dallas speaks out after Dixon High School shooting

DIXON, Ill. (WIFR) -- The school resource officer being called a hero for stopping a shooter inside Dixon High School is speaking out about that day.

"I couldn't believe it. But being mad, being dad and being the patrolman, the SRO there, I wasn't gonna let him get away," said School Resource Officer Mark Dallas.

For a few minutes during graduation practice on May 16, Dallas held the lives of all of Dixon High School students and staff in his hands.

"I was sitting in our athletic director's office talking to our athletic director and his secretary when I heard several shots ring out," said Dallas.

Dallas confronted the teen in the hallway. Illinois State Police identify the shooter as 19-year-old former student Matthew Milby, of Dixon.

"My son told me later, he goes, 'I heard you yell so loud, I knew it was serious," said Dallas.

"I didn't want him getting away because we had a lot of graduates coming in the school, some of them running late sometimes, so I knew the direction he was running off in, there was a possibility of other students being out there," said Dallas.

Dallas says Milby fired at him several times before he fired back hitting the former student in the shoulder.

"Every [second is a life] in that situation, so I'm just fortunate I was down there and that's the hard part - running the 'what-if's' through my head and stuff like that," said Dallas.

Thanks to Dallas' quick action, every senior at graduation practice, including Dallas' son Josh, walked across the stage the following Sunday.

"It's hard to talk about it sometimes without shedding tears, and even seeing my own son and getting that hug that day - it was wonderful," said Dallas.

Officer Dallas says he wants to thank everyone in the Dixon community and beyond who have been so supportive through this whole situation.