bio caddy

Ok, about a week and a half ago I accidentally hit the car next to mine while backing out of my parking space. I got out and looked for damage and I had scraped against the door handle. I left a note but I haven't been contacted by anyone, I didn't even see the scraped handle until after I had breathed a sigh of relief that their was no damage (unfortunately I was wrong). I know since I left a note it isn't technically a hit and run, but I'm afraid the note fell off. What scares me the most is where this happened. It was in my county's courthouse parking lot. That's right next door to our towns police station. And I've never actually seen any security cameras outside of either of them. I'm hoping that the person I hit just didn't think it was worth the increase in insurance for a scraped door handle. But I'm afraid that if I am accused of a hit and run they may try to rail road me for it happening in their own parking lot. And If it was a judges car I'm sure I'm screwed… So, what are the chances that that would happen? I only had one piece of paper and I used that for the note I left so I didn't write down down the other license plate. If they do manage to find me and accuse me of a hit and run, how long would it take for them to find me if the note was lost. No one contacted my insurance company either. Any advice would be welcome.