Martin Bruce White(マーティン・ブルース・ホワイト) is a member of IDEAL and associate of Billy Craig. He is an American serial killer known as "Martin the Griever."
Though he comes off as timid and likable, he has a hidden personality that comes out once he considers his victims as friends. This real persona that appears during his homicides craves bereavement, and so he then kills those that he grieves for.
He first appears when Kakerou identifies him entering Japan under a false name. He is then seen with Craig at the negotiation with Mizue Yuuko and attempts to kill Lee and Ron.