Black Panthers were not and are not a prison gang as far as the history books I've read.  They were not even racist according to their creed although they may have had racist members they even had a white branch of the party and one of their founding members, Bobby Seale, dated Jane Fonda who was and is white.

There were and are racist groups in all corners of society, but by nature and constitution, they were not.  At least the ones in the 60's and 70's.