Properties can appear have a GREAT value however in high crime area. Some areas of Dallas many agents refuse show properties in HOWEVER that is their personal preference.
Seriously, besides talking to the local precinct in that neighborhood, also talk to neighbors up and down the street. Ask several and you'll get an idea. Also, look for graffiti also known as "tagging" on signs, walls, etc. This is also a good indication of criminal activity. Depending where you live, certain police websites can show you on a map all crime activity in that area using different symbols for different crimes.
Also, check for vacant, abandoned houses in that neighborhood. They could attract crime to that area in the future, the longer their left vacant.
Often the best resource for neighborhood safety issuea is the local police department or the county sheriff's department. they have access to the most current and accurate information and are generally very willinf to be helpful.