Your best source for info on crime is the local police department.
I would suggest that you pick up the phone and call a lender or two and go from there. You may also call a local realtor and ask for a lender referral from the realtor.
First things first. Fix your credit. In the early 2000's money was easy and lots of people with bad credit bought houses and then in the late 2000's many of those people lost ... more
I don't know where Trulia pulls their crime data from, but you can also get the most up-to-date information at http://www.sanantonio.gov/SAPD/CrimeandCallInformation.aspx