brown falcon or black falcon?

Dear Fellow Birders,

I was hoping someone could help identify this picture:

jpolak.org/falcon.jpg (~140kb)

My thoughts are either Black Falcon or Brown Falcon juvenile. I am
heavily leaning towards Black Falcon because this individual doesn’t
seem to have the ‘Brown falcon teardrops’ on the face, and we have seen
plenty of Brown Falcons.

Staring at the illustrations in Pizzey & Knight are confusing, though
pictures on Graeme Chapman’s website seem to suggest it’s Black Falcon.

This picture was taken at the Western Treatment Plant yesterday.

Thanks for all the help!

Sincerely
Jason