The movie, in fact, gets a big laugh when a precinct boss (Brian Dennehy) asks the two men if they plan to retire.
They answer with a happy, obscene "no," a moment that not only defines their characters, but works as a reassuring, sentimental nod to loyal fans.
Pacino and De Niro aren't going anywhere, and certainly not gently.
That said, you'll also notice that "Righteous Kill" isn't asking either actor to stretch. World-weary, rule-bending cop? I think they can handle it. And the story is hackneyed - veteran detectives on the trail of a serial killer who leaves rhyming poetry at the scene of his grisly crimes.
Aside from the novelty of two acting legends working together, "Righteous Kill" plays like a pumped-up episode of "Law and Order," with the lurid benefits of the "R" rating.
De Niro accrues most of them. He's romantically paired with the gorgeous and much younger Carla Gugino, playing a CSI detective who's aroused by violence and by her lover's Dirty Harry reputation. They retire from grisly crime scenes to have sweaty, urgent encounters - kudos to cinematographer Denis Lenoir for finding a way to photograph these scenes in such a way as to feature Gugino and obscure De Niro.
This is also played for laughs, up to a point. The older man's fatigue at meeting the needs of a younger woman are fodder for crude jokes.
Gradually, though, the movie gets darker and asks to be taken more seriously (the CSI gal's taste for rough sex leads to a truly awful scene), and here's where it runs into problems.
"Righteous Kill" tries to build suspense around the idea that one of the detectives emerges as a suspect in the killings - director Jon Avnet even uses an apparent confession as a framing device, tipping us in the early moments to the culprit's supposed identity (a flashy device that's overused and disrupts the flow of the movie).
If we assume this is a misdirection, it's not very difficult to determine where the movie is really going, especially if you pause to chew on the movie's labored chess metaphors.
Why, you wonder, would titans like De Niro and Pacino opt to participate in such a pulpy, throwaway "B" movie? For one thing, they're obviously having fun. And if you consider the ending of "Righteous Kill" in the context of their overall careers, you see there's a ghoulish symmetry to it.
When, and if, they ever retire, it's something they can laugh about. *
Produced by Jon Avent, Boaz Davidson, Randall Emmett, directed by Jon Avent, written by Russell Gewirtz, distributed by Overture Films.