Extremely dangerous dog owner. They are keeping an aggressive dog off a leash... It's a tragedy waiting to happen, could be a child next. It sucks because I'm sure they love their dog and genuinely don't belive its aggressive, but it has to stop.

That said, definitely take pictures of the dog off leash if you can, and present them to the police. Get video, if possible, of any altercation. It's your word against theirs unfortunately, and you need evidence if you are going to court.

You should be free to walk your dog without that risk.

Really sorry to hear about your dog, but glad she was able to defend herself, a lot of times it's very one-sided and "over" quickly...