Yeh, I woudn't involve the law into this. Maybe try talking to her and explaining your relationship and how you got to this decision. Tell her that she still means alot to you just you weren't the right kind of people for each other. And say you would like the pictures back because they mean alot to you, of all the good times and memories and that she will never be forgoton. Tell her don't be mad cause it's over, be happy because it happen. I don't know your girlfriend but if she is reasonable try this and maybe she'll understand. She is probably just abit upset right now. When I broke up with my g/f 2 weeks ago
she wanted to give me all the stuff I gave her back. But I wouldn't let her, I told her it was a gift for her and what she wanted to do with it from there was her choice.
Take Care & Good Luck,
§am.