I hope this helps.
If not, other things you can do are to speak to the neighbors, or even people that don't live there but are there often that can give you non-bias information such as the mail delivery people or local pizza delivery companies. I would also recommend driving through later in the evening for a better feel of the area.
Mission San Jose, Warm Springs, Ardenwood, Niles, North Fremont/Centerville.
Remember this is based on news reports, personal experience, and driving in the areas., not science. I probably have offended some folks, and will get vehement denials, but buying a house is a huge (and now especially 'risky' ) investment and you need to have all information (real estate agents can't tell you this conveniently, so they are not so useful in this instance) you can get before pulling the trigger.
Good luck. BTW Look at the police crime blotter in the local paper and that gives you a good idea. I am sure some enterprising person has aggregated this data somewher.