Can Anything Be Done?

I'm still trying to get a grip on the tragedy that occurred the other week and am almost able to talk about it now. Now, I'm feeling more angry. At first I'd been extremely angry/frustrated/upset/hurt/uncomprehending. Then it went from sad to angry and that feeling that something is missing, something I've forgotten. Unacceptance, denial. I WANT HIM BACK! How can someone just nonchalantly RUN OVER a little dog and do nothing about it! I MISS THE LITTLE GUY and feel there should be some RETRIBUTION! I just don't know what to do about it! How can he not know? We all saw it, just in the hysteria could not get a license number or say without a doubt that it was HIM even though we were all pretty sure about the truck.
  I'm just angry about letting it go. It's not like the dog ran into the street, he was just standing towards the side of the road with plenty of space in the middle of the street for the car to pass. I see it over and over again in slow motion. That truck running over my little buddy in slow motion, seeing him moving up under the wheels and having to close my eyes at realizing I'd see him go under the rear tire! WHAT CAN BE DONE ABOUT IT!? Is there anything that could be done since the dog was not on a leash? I'd just gotten home and opened the door. He went across the street to bark at the neighbor putting away the trash can. He'd just started warming up and getting adjusted to being here!