Are you really shure that this is an american alligator? Because on the picture it looks as if this specimen has a narrow snout and other things make them looking much more like a (estuarine/saltwater) crocodile.
You're probably right. I was going by the teeth, which looked to me as if they sat inside the jaw (I'm not much of a crocodilian person, so that's the only identifier I was familiar with). But there was two years between taking the photo and posting it here, and it was mixed in with alligator photos in my files.
If someone else confirms it's a croc, I'll change the heading.