It doesn’t spoil “Patriots Day,” the new thriller about the Boston Marathon Bombing and the hunt for the bombers, knowing this. Mark Wahlberg, as a “suspended and then redeemed” cop at the center of the action, is playing a fictional character, a mouthy, obsessed F-bombing Boston cop cliche.

But it does mute the impact of a docudrama  that feels like fascinating, as-it-happened history. It’s more “Sully” than “United 93” or “Zero Dark Thirty,” movies which proved you don’t need to invent characters in multi-point-of-view narratives to tell a true story.

Still, you get Mark Wahlberg, you get your movie made.

And it’s an otherwise noble enterprise, a detailed and action-packed account of a city’s darkest hour, and it’s professional, passionate response to it. Peter Berg, Wahlberg’s and Hollywood’s go-to guy for “true story” action (“Deepwater Horizon,” “Love Survivor”) has delivered a taut, riveting police procedural that maintains suspense even as it finds humor in the people, their funny accents and way with profanity, and pathos.

Wahlberg plays Sgt. Tommy Saunders, a demoted detective serving out a suspension in uniform, watching over the finish line of the 2013 marathon. You can tell he’s a fictional character by the special interest the Boston Police Commissioner, Ed Davis (John Goodman, rock solid) takes in him, by the number of other cops who and high-ranking officials who pat him on the back and remind him “These guys look UP to you.”

He’s a little distracted on the job, not that he could have seen or prevented what happens on that April 15, the 117th running of the race.

Berg gets us to the blast in the film’s first 25 minutes, and uses hand-held cameras (dropped to the ground), CCTV footage, archival footage and sound — tinnitus-like ringing tones in the score, concussive silence after the blast — to put us in the moment.

There is blood and torn flesh everywhere — a dead child, a disembodied foot.

And then there is professionalism. “All medical personnel to the finish line!…Confiscate all cell phones!”

The narrative also follows the bratty fanatic Tamerlan Tsarnaev (Themo Melikidze, simmering with resentment and menace) and his even brattier, bullied and callous teenaged brother Dzhokhar (Alex Wolff, terrific). We see just the barest hint of their preparations.

Kevin Bacon is Special Agent Richard DesLauriers, the FBI man who looks over the bomb-shrapnel, calls the act “terrorism” and heads the investigation.

Berg handles of the unraveling of the mystery in brisk, nervy strokes. A great (fictional) moment — summoning the cop who knows the finish line streets (Saunders/Wahlberg, of course) to walk through a mock-up of it, recalling where the right surveillance cameras are that would have captured the bombers as they walked into the crowd to make their mayhem.

Legions of agents flip through video footage and ID the images that will give up the murderers.

But many stories are folded into this narrative — the young couple, planning a cross-country move, who take in the race’s finish only to become victims, the very young and monied Chinese immigrant (Jimmy O. Yang), selling order-placing applications to Chinese restaurants, trapped in the manhunt after the bombing, the equally young MIT campus cop (Jake Picking) who fell afoul of the bombers as they fled town.

J.K. Simmons lends marvelous, world-weary bravado to the Watertown P.D. sergeant who wades into the epic firefight where overmatched cops cornered the brothers. That shoot-out is worthy of something Michael Mann might stick into one of his action epics. In this case, the bullets, bombs and cars blowing up really happened.

And through all the tension and violence, Berg (he co-wrote the script) adds layer of flavor and a sense of place to it all. Personable, sassy, F-bombing cops, comically “helpful” F-bombing civilians, aerial shots capturing the beauty of the city, street-scenes showing its working class standard of living.

The great Michelle Monaghan has one electric moment, playing Saunders’ wife, wild-eyed with relief as she seizes him the moment he gets home.

Aside from those invented characters, Berg plays this thing straight down the middle. There’s no Muslim bashing, “I’m not gonna let Fox News run this investigation” is spat out and the FBI admits, quickly, that it had the older brother on a watch list.

The result is a film that, like “Sully,” celebrates competence over bravado, sympathy for victims over revenge against the perpetrators, and the people of Boston over any attempts to circumscribe their freedoms, dampen their enthusiasms or clean up their language.

MPAA Rating:R for violence, realistically graphic injury images, language throughout and some drug use

Cast: Mark Wahlberg, Michelle Monaghan, Kevin Bacon, John Goodman, J.K. Simmons

Credits:Directed by Peter Berg, script by Peter Berg, Matt Cook, Joshua Zetumer. A Lionsgate/CBS release.

Running time: 2:13