“Strong Island,” the 2017 Oscar-nominated documentary directed by Yance Ford, was a deep investigation into the death of Ford’s brother and a jury’s subsequent refusal to indict the man who shot him. There’s a flavor of the same grief and fury that drove that film in Ford’s newest work, “Power” (now in theaters), which methodically builds a case against modern American policing.

Ford’s documentary is not the first on the subject, nor will it be the last. The intersection of policing and the justice system has been a compelling topic for documentarians for a long while now, spun up alongside investigative reporting that unpacks assumptions about law enforcement. The results have been kaleidoscopic in nature. Just to name a few:

• Stephen Maing’s “Crime + Punishment” (2018, on Hulu) followed the whistle-blower police officers known as the “N.Y.P.D. 12.”

• Peter Nicks’s “The Force” (2017, on Hulu) captured a seemingly unending chain of crises within the Oakland police department.

• Ava DuVernay’s “13TH” (2016, on Netflix) explored the roots of the prison-industrial complex.

• Theo Anthony’s “All Light, Everywhere” (2021, on Hulu) probed the pervasive role of surveillance, like police body cameras, in keeping order.

• And Sierra Pettengill’s “Riotsville, U.S.A.” (2022, on Hulu) took footage from fake towns built to train police to respond to civil unrest in the 1960s and turned it into a startling history of the militarization of law enforcement.

“Power” is most like “13TH” in its structure and approach, relying largely on historical context, archival footage of network news and political speeches, and a bevy of scholars and experts to explain an array of issues. How did policing and politics get intertwined? Why did American police become more like the military? What does the term “law and order” mean on the ground? How and why are armed officers involved with everything from patrols to strikebreaking?

But where “13TH” often took a poetic approach, “Power” mixes polemics and the personal. The aim, as the title suggests, is to underline how much of our contemporary conversations about policing are really about power: who is in a position of power, when can that power be used, and when is it given to others. Ford operates as narrator, his voice guiding us through the maze.

This is heady stuff, even if it’s not particularly new information. As with many documentaries that aim to construct a political and social argument, it’s a little like drinking with a fire hose, even if you’re familiar with the history and questions. The point isn’t the data, but the spider-web nature of the argument; seemingly disparate things (labor strikes, slave patrols, the removal of Indigenous Americans from their land) are drawn together in “Power,” which becomes an act of pattern recognition. It is not easy viewing, but it’s a strong introduction to a topic that seems freshly relevant every day.