The police aren't the ones stalking this guy... Asking witnesses for a license plate, casing the same intersection, asking other firefighters, etc.
Put yourself in his place...."I accidentally hit a kid. I was shaken up and tried to do the right thing. I stopped, he said he was ok... I drove him home. He now is stalking me and called the cops. He hung around that intersection looking for me, he asked other people at my employment, he tried to find witnesses and get my plate number. I'm afraid what he's going to do now."
Based on the fact that he stopped and took responsibility I don't hunk he is evilly cackling his way home. I could be wrong but based on his actions that's my impression.