I'm going to refer you to the Baltimore City Police crime data maps. You can look in the last 90 days for crimes in any area of Baltimore City.
There's a link to it here: http://mdrealestate.wordpress.com/2007/06/12/find-more-interesting-statistics-for-baltimore-county-and-city/
Crime is anywhere and not just limited to "bad" neighborhoods. It's one of those sensitive subjects that Realtors can't talk too much about because it really is a subjective issue. I think the best thing you can do is visit the neighborhood at different times of day, as well as talking to neighbors.... more