If poverty contributes to violent crime, how come we never hear about trailer parks being shot up by thugs?

You don't hear it alot because it is not newsworthy enough, even when it happens in the hood it is not always shown on the news or someplace where everyone can hear about it. Alot of people don't care about poor people killing or shooting each other. its a choice of the media.

Living in poverty contributes to future acts of crime; the poor would probably have to steal from the rich, not each other - if you know what I mean.....

I know of a senior citizen who was shot to death through her trailer window by drive by shooters

Even thugs don´t beat up their own, they stay close to them. They hit those who are better off, and who live in houses.

Hmm.... good question!