Captain James "Cap" Hollister was played by Martin Sheen in the film Firestarter.
He was the head of The Shop. He is ruthless and even uses murder as a method, like he did with Joseph Wanless, the head of his scientific team, to achieve his goals, killing even his own people on the way through his own assassins like John Rainbird.
It is implied through John Rainbird, he has done more than enough crimes to go to jail for the rest of his life. He wants to have Charlie McGee for military purposes, because he sees Charlie´s power as a potential weapon to be used in an eventual conflict against an enemy of the U.S.A.. He recruited John Rainbird for that, though he later realises, that he is crazy.
He is later killed by him, when he shoots him under Andie´s influence.