ARLINGTON, Texas (CBSDFW.COM) – The Arlington Police Department says it’s investigating claims that bullying may have motivated 18 year old suspected shooter, Timothy Simpkins, to bring a gun to Timberview High School Wednesday, Oct. 6.

Assistant Police Chief Kevin Kolbye said others could be charged, if additional criminal acts are uncovered.

“Nothing’s off the table, but I also want to stress that even though there may be bullying or a fight, it still doesn’t justify bringing a weapon to school,” said Kolbye.

Cell phone video shows another teen tackling Simpkins in a classroom and punching him repeatedly in the head. According to a newly released police affidavit, a witness told investigators she intervened and managed to get control of the aggressor in that fight. She then turned around to check on Simpkins and found him holding a gun he’d pulled from his backpack.

“When this school year started, I told my mom I didn’t feel safe. That I thought there was going to be a shooting,” said Kyle Stamey, a senior at Mansfield ISD’s Ben Barber High School.

He says he regularly avoids the cafeteria and large hallways, worried he’ll have nowhere to run from a shooter.

He’s been a victim of bullying, he says, and he doesn’t feel Mansfield ISD takes security seriously.

“I really hope something changes. I’m not worried about me. I’m worried about my sister at this point,” he said.

The district does have an online system to report bullying and policies on how to respond to the reports.

“The safety and security of our students and staff has always been and will remain our number one priority – both physically and social-emotionally,” read a statement from Mansfield ISD Thursday.

But a Facebook group with nearly 700 members, MISD Parents for Change – Anti-Violence and Bullying, calls itself “a group of parents who feel that bullying is being swept under the rug…”

“It’s a huge issue right now,” said Christopher Wright with the Texas Anti-Bullying Coalition.

The organization says bullying can lead to loss of learning, depression, and in extreme cases, suicide.

“It’s 24/7. There’s cyberbully, there’s bullying in school, there’s bullying after school. It’s just all the time,” said Wright.

Mansfield ISD made counseling available for students Thursday and will resume classes Monday, Oct, 11.