It’s the famous walk, a steady, cat-like lope that hasn’t changed with the decades, the way he turns on a half-menacing/wholly insincere smile when he needs it.

It’s the way he lowers his head and raises his eyes in glowering disdain, the patience he gets across with his pauses, the eye that wanders over a co-star playing a suspect, an apartment dressed as a crime scene.

With Denzel Washington, it wasn’t just one big thing, it was all “The Little Things” that he pieced together in performance after performance that ordained his stardom.

Pack him in an autumnal thriller with two other Oscar winners and some of the years melt away, even if no high-mileage Kern Co. California sheriff’s deputy could spend that much time and effort on Hollywood dentistry. Especially in 1990.

“The Little Things” is a solid, downbeat mystery thriller that uses three sharply-observed performances to surf past its shortcomings. Writer-director John Lee Hancock (“The Blind Side”) serves up an old fashioned star vehicle/police procedural that turns into a game of cats-vs.-mouse once our detectives have a suspect in mind. It’s a story whose implausibilities lessen in importance every time Washington shares a scene with either Rami Malek (“Bohemian Rhapsody”) or Jared Leto (“Dallas Buyers Club”), especially when all three are in the frame together.

Washington’s “Deke” Deacon is a “detective” in the past tense, only. These days he’s a sheriff’s deputy, low enough on the totem pole to be the guy the boss sends to LA to collect a piece of evidence for a case, old enough that we recognize, in an instant, that there are reasons this guy was never promoted.

The evidence, being used in another case the LAPD is helping prosecute, puts Deke into the same room with an old partner (Terry Kinney) now a captain, and in the field of view of the hot new “college” detective, Sgt. Jim Baxter (Malek).

Somebody is stalking young women. We’ve seen the duct tape in the trunk of the faceless driver pursuing somebody through a lonely corner of a SoCal night.

For Deke, stuck in LA an extra day waiting on his evidence to clear processing, the case brings flashbacks and curiosity. Baxter is a “good cop,” a “face of the department” type, idealistic and pious. He’s eager to size up the Old Guard.

“I hear you’re a good cop,” Deke offers.

“I hear things, too.”

At Mike’s invitation, Deke ends up at a crime scene, picks up a few loose ends Mike’s team has missed, and that invitation becomes an open one. Let’s track this serial killer together.

Hancock works entirely too hard to throw these two together and procedures and protocols out the window. He manages the suspense well enough and is expert at structuring a thriller that will attract stars and toss in a surprise or two, if no more than that.

His dialogue is packed with bromides and cop-picture cliches, the “something I gotta know” questions, the sharper-than-he-looks suspect who invokes famed crime photographer Weegie when dismissing crime scene photos.

But the characters are fleshed in nicely, with Malek’s Baxter lecturing his underlings with a line he must have heard on any number of “C.S.I.” TV shows.

“From now on,” he says, stopping any light talk of a dead woman, “we work for HER.”

Onetime Joker Leto, Manson-bearded and Manson-eyed, brings a lipsmacking villainy to Suspect One, a guy who may have access, means and mentality to do these awful things, or may just a working stiff with a psychotic passion for messing around with cops.

Washington gives a haunted touch to Deke, although there’s a lot of image polishing in both his “dark” past and demoted present. He hasn’t crawled into a bottle, and his sins seem pretty PG in light of policing problems in modern America. But this was pre-Rodney King, remember. Deke is allowed the luxury of seeing potential victims in every coed-packed convertible.

Deke’s promotion-free career gave him the chance to master his craft, which might have mastered him.

“It never goes away,” he confesses at one point. The flashbacks, the sincere conversation with and promise to a corpse once the coroner (Michael Hyatt) has shown him the road map of her demise, all show how this awful work weighs on him. The murdered, he tells Mike, “they’re your lifelong responsibility.”

But the old dog savvy and the instincts remain.

“It’s the little things,” a detail picked up at a crime scene, a tiny mistake the killer made, “that get you convictions.”

And its the pleasure of this cast’s company — grounded, detailed performances with a flourish here and there — that make this otherwise routine thriller pay off.

MPAA Rating: R for violent/disturbing images, language and full nudity 

Cast: Denzel Washington, Rami Malek, Jared Leto, Michael Hyatt, Terry Kinney and Natalie Morales.

Credits: Scripted and directed by John Lee Hancock. A Warner Bros./HBO Max release.

Running time: 2:07