Kim, I noticed on Trulia it has a "crimes" Tab on the listing information. Go to the listing on Dolores St , scroll down to the map, and click on it. I dont know how accurate it is, but it is there. The different websites out there are great too, but if you are looking at homes and get the chance to talk to neighbors, most love to talk about their neighborhoods....Driving thru at different times of day or week tells alot. A neighborhood where everyone is working on their yards on a saturday morning is always a good sign. And do remember, the best neighborhoods will eventually have an "incident" just because our city is so large and news is so instant that you will hear about it.
Let me know if have a Realor helping you yet, feel free to check out my website, too.