Is there anything you can do about people putting stuff in your mailbox?

I have had someone put naked photos in my mailbox with writing all over them and profanity and a bunch of unnecessary things. They did however word it and put something in it only a select few people I know know about me. I was wondering if there is anything i can do legally. If so how can i prove it? Can i give them the people i am pretty sure is harassing me and they fingerprint the photos and them and if they match voila. I am just looking for some help in the matter any would be appreciated thanks.