High school bans backpacks to make school safer

Funny thing is that if this is true: Most of the school shootings are done by someone just walking into school with a gun.
I mean honestly, how are you going to fit an AR15 in a fucking backpack? Unless you're planning on going hiking after a day of education, then you're not going to have many places to put the thing.
Most of the time someone just walks into a school with ill intent.