Just when audiences thought they'd heard the last of the demented killer Jigsaw (Tobin Bell), here comes Saw IV, continuing his trap-filled legacy -- this time, targeting the last remaining officer who has touched the case, SWAT Commander Rigg (Lyriq Bent). As FBI agents Strahm (Scott Patterson) and Perez (Athena Karkanis) begin to dig through the remains of Jigsaw's crime-scene hideout, a new puzzle presents itself, with Rigg as the pawn in another deadly game filled with moral quandaries and torture-filled traps. At stake is the life of his superior officer Hoffman (Costas Mandylor) as well as his friend and fellow cop Eric Matthews (Donnie Wahlberg), whose abduction by a now-dead Jigsaw triggers an obsession in Rigg that will haunt him til the grisly end. Director Darren Lynn Bousman returns to the series after helming both Saw II and III, with a script penned by Feast writers Patrick Melton and Marcus Dunstan.
~ Jeremy Wheeler, All Movie Guide