Logan, your good heart must be eaten up by this! It must be so hard for someone who loves dogs and people so much. I admire you so much for thinking about the consequences so fully before acting.....not something I am well known for!
If I were in your position I would call the RSPCA who would then come and assess the situation. Any photographs, tape recordings or video tape that I could take would be shown to them. They would then approach the owners and take it from there.
I have no idea if any organisation your side of the pond can do this sort of thing?