go to the bottom of the Trulia listing and there is a map with tabs on it, click the Crimes tab and it shows a map.
Check out Crimespot.com or Houston police dept's website, too.
Houston is so big and diverse that even though we are not in the top 10 for crime in the country,
it is still best to check with the locals, drive thru the neighborhood at different times of the week or day to see how the neighbors take care of their property, how the traffic is, and just the general vibe of the neighborhood.
Good luck, and if you need a Realtor, check out my website and send me a messege.