Distressing evening

So, this is all based on circumstantial evidence and even a bit of racial profiling, so it is very possible that I am completely out of bounds on this one... but I am still a little freaked out about it. I came home last night and the group of guys, my polite druggy crew (a few more than normal), were hanging out at the neighbors like always. I noticed that they had a new dog that I hadn't seen before, so I went over to say hello. When I got there, I noticed the dog was covered in blood. I asked what happened and they discussed something in spanish really quickly, then told me he had run into a tree. Now, I've had dogs stick their silly heads into bushes before, and come out all scratched and battered, but even so this seemed a little excessive. I didn't think about it too much though, and went back to my place. Later, as I was putzing in my garden, I heard them talking, in spanish, about that dog and my neighbor's dog (both pitbuls, of course) fighting. And their carport had a rather large puddle of blood in the middle. Now, I don't know that they had a dog fight, but it sure looks suspicious. For one, Nathan, the neighbor's dog, is the sweetest, most submissive thing. He wouldn't get into a random fight, only if he was pushed into it. Secondly, they lied. Told me he ran into a tree. If the dogs got into an unplanned fight, they probably would have just said so. Finally, one of the guys, who I haven't seen there before... watched me the entire time I was out putzing in my garden. Not like, 'ooh baby, she's hot!' but more in the 'what is she going to do' sort of way. I must admit I am a little scared. All the other guys there are a lot of bluster and talk, but this guy, as unassuming as he was, he exuded power.
So, I don't know anything, but it sure looks like they had a little dog fight for kicks. Something I find wrong on many levels. But, I have no proof, and I must admit I am a little scared to report anything, because they would know it was me... and who knows what they would do.