It's a pied version of the Rock Pigeon ( _Columbia livia_ ), aka Rock Dove. According to the Cornell Lab of Ornithology, the pied variety of Rock Pigeon is one of any color that has splotches of white on the body. I think that fits your bird very well. It's not a different species, but just one of several color varieties of Rock Pigeon.
If you are not familiar with Cornell's site and enjoy birds, their All About Birds site is very nice.