Del Toro makes a great detective paradigm, doing a good deal by doing very little.

But when that tired old ditty comes on the car radio, sometimes we happily hang with it. Director Grant Singer’s first movie, on a resume consisting mostly of music videos, Reptile doesn’t hurt going down — and what is there about a professionally executed, paint-by-numbers genre spritz that can’t kill a Friday night? In this iteration, Benicio Del Toro is the transplanted small-town cop and member of a tightly bound couples-dinner detective fraternity that includes his captain (a weary Eric Bogosian) and the obligatory fat bulldozer asshole (Domenick Lombardozzi), whose effusive lack of couth is the first familiar red flag. The hero’s saucy wife (Alicia Silverstone) sometimes helps with the investigative head work, while flirting with the hunky young contractor working on their house. Meanwhile, a local hotshot realtor (Justin Timberlake) finds his young girlfriend butchered in a for-sale McMansion and instantly becomes a suspect, as does the greasy-haired ex-con lurking around (Michael Pitt) and the victim’s drug-dealing ex-husband (Karl Glusman). Somehow, Frances Fisher, as Timberlake’s controlling mogul-matriarch of a mom, isn’t immediately considered a culprit. Obligingly, the sins of the past, in the shape of real estate skullduggery, start to slowly emerge, and Del Toro’s watchful flatfoot starts to realize….

You work out the rest. The measure of such a film has to rest with the particulars and the textures, which here are often rote but solidly wrought. Del Toro, who also co-wrote and co-produced, may have been after something meatier, but he ends up being the film’s only home run. With his big craggy face, sleepy basilisk eyes, and entirely unmodern pompadour, Del Toro makes a great detective paradigm, doing a good deal by doing very little and effortlessly conjuring an affect of secretive attention. In fact, he seems a little too gloweringly intelligent to be chumming with these dumb cops and line dancing with his wife at the local cowboy bar. The writer/producer in him might have been a little confused about his import as an actor, but at least he’s here, sneakily eyeballing the story along in a way that’s more interesting than the story itself.

There are deets that are gratifying — the cumulative firefight is refreshingly spontaneous, Silverstone’s fast-thinking wife proves instrumental and not just decorative, and the film’s efforts toward realism result in a few strands of baffling randomness. (The hero becomes quietly obsessed with an electric-eye kitchen faucet at the murder scene, orders one for himself, and in the end has it triumphantly installed.) But do not expect surprises from Reptile — only the chill of Del Toro’s glare.