Detective movies used to be as common as vanilla ice cream, but they’ve vanished from the studio film landscape. Praise be to canny indie filmmaker John Sayles, who revived the genre, gave it a modern twist, and pushed it out onto the mean streets of bordertown Mexico.

His 19th feature, “Go for Sisters,” reminds us that you can give characters guns and tense face-offs without creating brain-dead action trash.

A novelist and screenwriter turned director, Sayles is one of the fathers of the American independent film movement. His films have a singular vision and not many compromises in the telling. He creates multifaceted characters whose personalities drive the story; the brute hand of plot manipulation is rarely felt. Here he takes classic Southern California noir, a search for a missing person that leads to larger, dangerous revelations, and adds engrossing players and lively twists.

“Go for Sisters” upends the usual boys-only world of sleuth films by putting a pair of women at the center of things. Back in high school in Compton, Bernice (LisaGay Hamilton) and Fontayne (Yolonda Ross of HBO’s “Treme”) were so close people said they could “go for sisters.” Twenty years on, Bernice is a parole officer and Fontayne, an ex-con and former addict, is on her caseload.

Approved procedure is to transfer old acquaintances to other agents. But Bernice’s son, Rodney, has gotten into seriously shady dealings and disappeared. Fontayne, who knows the criminal element better than her deskbound former friend, owes Bernice a favor. She agrees to help find Rodney without involving the police. The pair hire Freddy Suarez (Edward James Olmos), an LAPD veteran who left the force under a cloud of scandal. Together they head to seedy, violent Tijuana (“a theme park for bad behavior” he calls it) to find Rodney before his ruthless enemies do.

The film doesn’t rely on nail-biting confrontations to draw us in. Sayles is a restrained filmmaker. His interest is human nature. A crime yarn, with its currents of risk and redemption, is just a vehicle to reveal it.

“Go for Sisters” is a tapestry of character portraits, story lines and sociological observations. The arm’s-length but ever-evolving relationship between Fontayne and Bernice provides a solid emotional core. Freddy’s gradually revealed back story amps up the suspense as we come to fear he may be unsuited to the dangerous job. Even cameo players, like the Mexican tavern owner played by Hector Elizondo, or the cocky drug dealer played by Harold Perrineau, are rendered with depth and humanity.

Olmos, who also produced, shines as the retired lawman, who stepped up to help a friend and ended up disgraced. On the beat he was called “the terminator.” Now he’s edging into old age, struggling to keep up with his house payments.

Hamilton plays the high-strung, complicated Bernice with assurance, but it’s the effortlessly magnetic Ross that you can’t stop watching. She gives Fontayne a soft voice and shy demeanor that conceal a spine of hardened steel. When the film is over and the hubbub about drug-running and human trafficking settled, I found my thoughts drifting back to these three individuals. In a way all too rare today, they quietly, gradually got under my skin.