John Rain.

About John Rain

John Rain is a fictional character created by Barry Eisler. He appears in eight of Eisler's espionage novels as an assassin for hire who specializes in making his victims appear to have died of natural causes. Rain is a Vietnam War veteran who served with the Special Forces; he was later recruited by the CIA, but by the time he appears in the first of the "John Rain" novels, "Rain Fall", he is working "freelance," offering his assassination services to any client willing to follow his three rules: 1) No women or children, 2) No secondary team working separately on an assassination Rain is handling, 3) Principal actions only.