CHICAGO (CBS) – Students were seen running outside of Dixon High School Wednesday after a former student brought a gun to school and fired shots.

The School Resource Officer, Mark Dallas, shot and wounded the armed suspect in an exchange of gunfire outside the school.

The suspected gunman, 19-year-old Matthew Milby, is a former student at Dixon High School.

Matthew Milby’s mother spoke to reporters about what may have led to the shooting.

CBS 2’s Suzanne Le Mignot reports the alleged gunman’s mother, Julie Milby, says her son was bullied and recently had been beaten so badly, his jaw was broken.

She says while he endured the injuries, others watched, no one offering to help him.

Just over an hour ago, authorities, including ATF agents, entered the Milby home, armed with a search warrant.

Julie Milby says she has no idea where her son, Matthew Milby, could have gotten the gun he’s accused of firing at Dixon High School.

She says recent bullying has left her son troubled.

“What was hurtful was and what this all led to was ostracization,” stated Julie Milby. “I just know that the kid’s been real sad for a long time.”

She says a lot of kids stole from him, claiming they were kids he’s known all of his life. “His kindness got taken for weakness and he kind of got thrown under the bus.”

Published reports say the former student was recently expelled. His mother says he was still a student at Dixon and was supposed to graduate this Sunday. He had been on the school track and football teams.

When asked why her son was kicked off the football team, Julie Milby responded, “He got caught smoking pot and that happened and he got some help.”

Police reports show a marijuana possession charge for Milby and an arrest for criminal trespass to railroad property.

Milby’s mother had a message for the officer who shot her son, thanking him and saying she’s grateful her son didn’t die.

Police say Matthew Milby has not been charged at this time.