Your young(ish) Jack Dempsey looks like a male to me. Once again though, the identification experience and expertise of the 'details guy' here (Mr. Chhromedome), will definitely help to confirm what you have.
I know I'm late to the party but I'd like to add I also believe it to be a male. The dorsal and anal fins are elongated, the head/jaw are more robust and he has the coloration of typical males.
He look wonderful! Great JD!