Richard:
I've seen a Cooper's Hawk several times over the last few weeks hanging out between Dieppe Park and Donlands Ave. One afternoon it was roosting in a tree on Memorial Park a block east of Donlands, and I had quite a long and leisurely look at it. There's a colony of pigeons that congregate on the seniors' residence across the street from the Catholic school. Might be your bird, but on the other hand the Redtails do come into the neighborhood from the nearby ravines.
Cheers,
Ed