4. David Toschi - Zodiac (2007)
Warner BrosZodiac can be a difficult watch; not only is it based on the real events listed in Robert Graysmiths book of the same name but it also exudes the unnervingness and moral repugnance of the actual case. The killer was never caught but he leaves a generous supply of clues which allow political cartoonist Robert Graysmith (Jake Gyllenhaal) to thoroughly piece rogether a case against a man who may or may not be guilty while the police faff about doing very little. Mark Ruffalo gives a superb performance as the dogged officer David Toschi who eventually becomes the scapegoat for the incompetancy of the San Fransisco Police homidicide division and is demoted for apparently forging a Zodiac letter. This is of course untrue of the man who does everything by the book because he has been brought up believing in objective justice. Toschi was famous at the time of the case for having tutored Steve McQueen for his turn in Bullitt and inspired Clint Eastwoods Dirty Harry. Rather than playing him as this Holywood hotshot, Ruffalo gives a far more gritty portrayal of the man whose career was murdered by the Zodiac killer. Toschi eventually becomes a point of contact for Gyllenhaals character, providing him with some vital information to build up the case which cost the cartoonist not just his job but his marriage.