What causes children typically from an inner-city to be violent, and have PTSD?

They have nothing else to do but run with gangs & hang with them.  They don't have yards to take care of. No garden to water, not stock to tend to, no where to have hobbies,  It is the only thing they can do & you know the results. Pier pressure matters most of all, you can't get away from it.  They are a danger to themselves & others.

I can't stand to live in an apartment, it is just too close to my neighbors.  I live on the outskirts of a big city, well it is big to me.

I grew up in the inner city and I'm not violent. 

A lot people assume that people from the inner city are.

People don't get PTSD from living in an inner-city. They get it from experiencing trauma. I have worked with children who have PTSD and they come from all walks of life. Some have been abused, neglected and abandoned and suffer greatly from it. These children come from homes that are lower to upper class.

Children who are violent have usually witnessed or experienced it.

they probably learned it at home or from other kids