What type is this falcon I saw?

Question

This is what it was like:

There was a pidgen in the tree, and the falcon dived down and caught i out of the tree and pinned it to the floor. It then squeezed it so tight, the head fell off on the floor. It then starred at me and flew into the tree.

It was a light gray.

I thought it was a peregrine falcon. But they are rare.

I saw this in Hertfordshire, in the UK.

Answer 1

My assumption would be that it is a gyrfalcon, gray morph.  It's possible that it could also be a species of hawk--such as the northern Harrier or the northern goshawk.

Best,

Phoenix

Answer 2

May be a Gyrfalcon.Doubt that it was a Peregrine.