Police Chief AJ Deandrea of ​​the Colorado Police was one of those who met the school shooter in the violent school shooting in Columbine in 1999 where twelve students and one teacher were murdered.

Today he teaches his experiences to school staff. It is better to know how to act, than just wait for the police, he says.

- I promised the dad to one of the girls who died that I would make this mean something. That I would work to prevent this from happening to more children, says AJ Deandrea.

Increased awareness in Sweden

It's quiet and the audience in the school safety lecture in Uppsala is near tears when AJ Deandrea talks about the three school shootings he experienced.

In Sweden, it is extremely unusual to have deadly violence in schools. But today there is an increased commitment and awareness of school safety, says Maria Elmér, teaching council at the National Agency for Education.

- It is about doing a serious survey of what safety looks like at school. And to increase security, to prevent violence.

If you are in a metropolitan area, should you have such exercises with staff?

- Yes, it is important that the adults at the school feel secure in how to act in various difficult situations and have practiced it, says Maria Elmér.