For all of you who wondered:

Of course I gave the police the photos.

This story was pretty funny by itself, since they first asked me to print the photos and send them via (good old fashion) post.
It took me some time to convinced the officer that a digital file is best for everybody (exif, face recognition software, a bit faster etc.) until he was willing to give me an e-mail address.
(I'm not sure if it's a policy or technical difficulty but apparently they don't communicate with citizen via e-mail in the police here).

Anyway I promise to keep this thread updated with the following developments but it might take some time.

And I want to thank everybody for the warm feedbacks. I was a bit overwhelmed to see so quickly so many positive replies.

have a lovely day.