The sellers are required to disclose any issues like this, ex. if the police were forced to be called to their neighbors, etc. Other neighbors in the area would know about "terrible neighbors" so if this came out, they could sue the sellers and more importantly the selling real estate broker.
Is there a set of public domain resources for police calls by neighborhood and type?
Trulia seems to be using such info to create color-coded crime maps.
So ironically that's a feature my cofounder/CEO at Opendoor Eric Wu launched while he was at Trulia after they acquired his last company.