Righteous Kill pairs two cinematic icons whose previous screen collaboration, Michael Mann"s 1995 Heat, was absolutely electrifying despite minimal time together in a long movie. Now in their mid-60s, De Niro and Pacino are playing veteran cops who, despite being grizzled, should look much younger than these actors. The incongruent casting makes the dark story improbable from the get-go, and things get worse as dialogue by screenwriter Russell Gurwitz quickly sounds like a parody of vintage cop movie cliches. It"s a strain to find anything that works. The two leads play longtime detectives and partners whose weariness with rapists, murderers, pedophiles and other villains appears linked to the acts of a serial killer taking out bad guys who got away with heinous crimes. A videotape confession by De Niro"s tightly-coiled Turk--who has been seeking the killer with Pacino"s Rooster--would seem to establish his ties to the events. But the movie isn"t over until it"s over, assuming one is still with the movie after plodding along with its facsimile of noir conviction. Director Jon Avnet never gets a handle on Righteous Kill"s gritty heart, superficially pushing suspense along with heavy-handed editing, and adding unpersuasive sauce in the form of Turk"s somewhat S&M sexual relationship with a female cop (Carla Gugino).