How much gang activity is here in Houston?

So I Been here my whole life out in Cypress & go downtown on occasion for the astros but never in the more bad areas. I was just watching an episode of svu & it was abt gangs ect & It got me wondering how prevalent gangs actually are in the city. Aside from whispers among friends I never hear of gang activity like you do from places like NYC or LA. I'm not worried abt it or anything I just have a curiosity