Daniel Kaluuya stars as Fred Hampton, chairman of the Illinois Black Panther Party, in "Judas and the Black Messiah.". (Warner Bros. Pictures via AP)

There’s a shocking number near the end of “Judas and the Black Messiah” — 21.

That’s how old Fred Hampton was when he was chairman of the Illinois Black Panther Party, when he organized different factions of the disenfranchised to fight the status quo, when he was deemed enough of a threat nationally that the FBI infiltrated his organization and when he was killed by police under suspicious circumstances (law enforcement claimed it was self-defense; witnesses called it an execution).

Daniel Kaluuya is mesmerizing as Hampton in Shaka King’s film, capturing both the charismatic speaker in front of the crowd and the tender, quiet moments with Deborah Johnson (Dominique Fishback), his girlfriend and the mother of his child.

Kaluuya deserves all the awards attention he’s attracting (even if it should be in the best actor category instead of best supporting actor). But one thing the 32-year old actor doesn’t do is convince anyone he’s only 21 years old.

Here’s another shocking number that isn’t in the movie — 17.

That’s how old Bill O’Neal was when the FBI convinced him, in order to avoid prosecution for stealing a car and impersonating an FBI agent, to become an informant and infiltrate the Illinois Black Panther Party.

LaKeith Stanfield brings some nuance to a familiar character, the “spy” who begins to feel an allegiance to the person or group he’s supposed to bring down.

I didn’t know O’Neal still was a minor when the events started until after watching “Judas and the Black Messiah,” and all films based on true stories take liberties with facts. But as good as Stanfield is, a younger actor would have accentuated the power imbalance between O’Neal and Roy Mitchell (Jesse Plemons), his FBI handler. It also would have changed the dynamic of his relationship with Hampton, who must have seemed more like a mentor to O’Neal than a peer.

These aren’t fatal flaws. No younger actors come to mind who could have matched Kaluuya’s and Stanfield’s talents. And “Judas and the Black Messiah,” which opens in theaters and on HBO Max on Friday, is a very good movie.

The movie starts with O’Neal’s ill-fated car theft. He tells Mitchell he uses a fake FBI badge to steal cars because, in his neighborhood, “A badge is scarier than a gun.”

The screenplay by King and Will Berson shows how Mitchell cultivates O’Neal’s loyalty. He invites him to his home, wines and dines him, talks about his work on civil rights cases in the South. And O’Neal isn’t a tough sell. He’s apolitical and more concerned with self-preservation than advancing any cause.

And self-preservation remains O’Neal’s primary motivation longer than it normally does in these types of stories. When he gets caught in crossfire during a raid, he’s more angry that he didn’t get a tip from his handlers than he is at the unwarranted invasion.

Another wise choice in the writing and King’s direction is spending significant time on Hampton’s shy, tentative interactions with his girlfriend instead of focusing solely on his speeches and political leadership.

The look of the film — the cinematography, the production design and the costuming — as well as the music adds to its feeling of authenticity.

There’s no question that “Judas and the Black Messiah” is an overwhelmingly sympathetic portrayal of the Black Panthers with J. Edgar Hoover (a heavily made up Martin Sheen) and Chicago law enforcement as the villains.

The movie shows how the Panthers filled needs within the community — free breakfast programs for children, health clinics — to earn the respect of those beyond the black community, but it doesn’t shy away from the violence of the era. It does put it in context.

For those who grew up being told the Black Panthers were the flipside to the Ku Klux Klan, “Judas and the Black Messiah” either will be a rude awakening or it will be dismissed as revisionist propaganda.

But the power of the film and its effective use of documentary footage as a post-script is undeniable.

Review

WHAT: “Judas and the Black Messiah”

STARS: Daniel Kaluuya, LaKeith Stanfield, Jesse Plemons, Dominique Fishback and Martin Sheen.

STORYLINE: The FBI turns a car thief into an informant to gather information on Fred Hampton, chairman of the Illinois Black Panther Party.

DIRECTOR: Shaka King

RATING: R for violence and pervasive language

GRADE: B+