A veteran Irish-American lead and character player, Pat O'Brien is best known as one of the cynical reporters in the sterling first screen version of the Broadway play, "The Front Page" (1931), the title role (opposite Ronald Reagan) in "Knute Rockne--All American" (1940) and as Jimmy Cagney's clerical confidante in "Angels With Dirty Faces" (1938).A sharp, wisecracking type in the early 1930s, O'Brien found his star persona becoming increasingly sentimentalized after the Production Code crackdown of 1934, but occasionally returned memorably to his earlier type, as in "Torrid Zone" (1940),