He got into someone's yard and he and the dog that lives at that house got into it. Animal Control was notified. The pit was really good natured once the other dog was taken into the house, and seemed really really friendly.
I just hope that the owners can come forward to collect him, really, he was a beautiful dog, but I don't think I saw any tags or a collar either (again, really dark and I wasn't really interested in getting in between two fighting dogs, thankfully, the other people around weren't as sketched out by that as I was). So, if you are the owner, Animal Control has your dog.