The "fork" in the tail looks like it is because of the tail not being spread out flat. Just the weight of the tail would make it slouch and not square. Big fish tend to droop like this one is. A clear shot with out the tail being pinched is not there. The look of the color and overall shape I would bet on Brookie. Either way it is one heck of a fish. A scale sample would have been a good way to prove it a Brookie and it wouldn't have harmed the fish.