First, I would tell that NO city will list on any site, promoting tourism to their city, an "unsafe" part of it, as the idea is bring people, with the potential of perhaps relocating to that city.
A more efficient way of discovering this information would be to check the local government site and checking their crime demographics site, or even visiting the sites of the local law enforcement agencies. There are also many entities that dedicate their resources to tracking crime rates and statistics in particular areas of respective cities.
Another useful tactic would be to contact maybe friends or family that live in and know the area well. There is no better source of information than first-hand information, from individuals who are familiar with their surroundings. Real Estate agencies are also possible sources of information in this respect, though I would not say that they would be 100% accurate, as their goal is sell real estate and sometimes can be misleading.
I hope that I have answered this question accurately enough for you, and hope that you find a pleasant experience, in which ever place you should just to visit.
Also, it would be pertinant to note that every place has it's trouble spots, and randomness IS a variable in everyday living.