I like the two different expressions - the seemingly happy guy and the guy who's on his cell phone. They're doing their job, but don't seem too stressed over it! A bit blurry - when shooting stuff like this and if you have the option, crank up the ISO so you can use a faster shutter speed.
Drive by shooting? There is motion blur that leads me to believe this. Did you get out, talk to the men, explain your project and ask if you could hang out and take some pictures? I think if you had you'd have engaged them and gotten an image that draws the viewer in more and feel more for what they're there for. As it is, the guy on the phone doesn't make me feel for their cause. Tone, exposure, and post processing are good for this type shot.