Unknown Accipiter eating Robin

Video was taken July 10, 2007 at Parker Dam State Park (PA). This is a several acre grass overflow parking area which is surrounded by a day-use picnic area and extensive mature mixed forests.

I am unsure of the exact species. Could either be a Sharp-shinned or a Cooper's Hawk. I am leaning more towards a Cooper's Hawk based on the size of the bird and shape of the tail. If you have any insight on the proper ID of the bird, please comment.