Tsutomu Shimomura is a scientist and computer security expert, who gained fame when he, together with computer journalist
John Markoff[?], tracked down and helped
FBI arrest
cracker Kevin Mitnick. Markoff and Shimomura later told the story in
Takedown: The Pursuit and Capture of America's Most Wanted Computer Outlaw -- By The Man Who Did It (Hyperion, January 1996).