Hungry and/or angry people commit more crimes. That's just axiomatic. Desperation will cause those who had formerly been following all the rules to try something different in order to improve their situation. So social welfare as a bribe mainly helps that marginal fraction that would only shoplift if they absolutely couldn't pay. And there are a lot of people like that. It won't do anything about those who would shoplift for thrills, even if they could buy the whole shop, and it won't do anything about those who would light it up just to watch it burn. Those are relatively few.

I'd estimate at least 90% of people living under the poverty line would never choose to commit a violent crime or property crime if their survival needs were assured. Malum prohibitum crimes and regulatory infractions are another story. Having more money means you can smoke higher-quality marijuana, and usually with less police interference. Having more money means you can pay speeding and parking fines without spending any nights in the county jail.

"Poor people" are not just one big homogenous group. They have their righteous saints and their sleazy lowlifes, and everything in between, just like every other economic class. The former deserve society's help, whereas the latter can sometimes be bribed to behave better.

Welfare doesn't stop the terrorism that still happens in places that have welfare, because those terrorists aren't murderously mad about being poor. It certainly stops food riots, at least until the system collapses. The crime in the Chavez-unraveled Venezuela is quite different from terrorist activity in Europe.