The Death and Life of Marsha P. Johnson. Photo: Netflix

David France’s shattering new documentary The Death and Life of Marsha P. Johnson begins with its subject’s 1992 funeral and a procession in which men and women angrily scream at police, who stare ahead, blank-faced. At least the cops don’t beat them senseless, the way they might have 25 years earlier. Marsha P. Johnson had something to do with that.

The exuberant Johnson, a trans icon, activist, and drag queen who had a prominent role in the Stonewall riots and went on to live a very public life, was found floating in the Hudson a few days after July 4, when she’d told her friends that a car had been following her. The city classified her death as a suicide, despite zero evidence she’d intended to do anything but party into the night, get up the next day, and continue to fight the good fight. She was particularly incensed by alleged financial irregularities related to a Christopher Street festival. Twenty-five years later, aging activist Victoria Cruz of the New York City Anti-Violence Project (she was a contemporary of Johnson’s, but never met her), trudges around Manhattan and its environs playing amateur detective — likely getting closer than the pros to the truth of Johnson’s death.

Beneath France’s documentaries (the last was the award-winning How to Survive a Plague) are questions that never get less urgent. How do you remind young people that they’re standing on the shoulders of men and women who lived (and, in many cases, died) for rights they take for granted? And how do you get out the message that people are still dying and that historic injustices are still going unredressed? Like all good documentarians who depend heavily on archival footage, he and the editor Tyler H. Walk know how to ensure that the past remains in the present tense.

In this case, they’re aided by figures who hold the screen tooth and nail. Johnson is obviously one of them, but the film has another protagonist (and trans activist and icon) in her friend Sylvia Rivera. Objectively, you could look at the film and wonder why Rivera has been allowed to shanghai the narrative so often. Subjectively, you’ll have no doubt that France was captivated by the footage of Rivera and knew that we’d be, too, narrative line be damned. But Rivera’s life is not tangential. Rivera, Johnson (plus Cruz, quite the looker in her day) are central to the theme of an era slipping away.

Drag queens (the term sounds antiquated, but is both more vivacious and truer to Johnson and Rivera’s essence than “female impersonators”) were central to pre-Stonewall gay life in big and middling cities. At a time when you could be arrested for kissing someone of the same sex in public, these were the most obvious targets for harassment and persecution. At the same time, their presence in a bar was a signal that it would be reasonably safe for other gays to congregate. They were, if you’ll forgive me, the canaries in the Mineshaft.

Rivera’s story, France shows, is also one of rejection by the community for which she’d risked so much. The thinking among some gay intellectuals and their acolytes — before the “T” was appended to the end of LGBT — was that drag queens embodied retrogressive stereotypes. Also, they were a pain in the ass. The most powerful scene in The Death and Life of Marsha P. Johnson is not of Marsha P., but Rivera at a huge 1973 NYC gathering at which she is fiercely unwelcome, seizing the microphone and, to resounding boos, even more fiercely giving it back — an epic rant detailing the sacrifices by her and people like her for the privileges that these well-off white gays now enjoy.

It’s possible that Rivera’s disillusion with the gay-rights movement and retreat to Westchester (where she lived and hosted a cabaret for some years) saved her life and sanity, although later in the film she’s back living in a transient community by the Hudson when she and her fellow humans are “cleaned out” to make way for the riverfront park we all jog and bike along today.

If Marsha P. fades from the film (there is not enough great footage of her, I guess, although enough to suggest she could be irresistible), the sense of vulnerability she projects permeates the rest of the movie. Cruz also tracks the case of 21-year-old Islan Nettles, beaten to death in 2013 by a 25-year-old named James Dixon after Dixon flirted with her and then discovered — to the razzing of his friends — that she was not a cisgender female. The sparsely attended murder trial ends in a way that satisfies no one. The traditional defense of such murderers — that these men were so traumatized that they weren’t fully responsible for their actions — might be less persuasive these days, but the scent of it lingers like a decayed body.

France does come back to Marsha P. Johnson, of course. Cruz heads to the Downstate Correctional Facility to interview one of the last known people to see Marsha Johnson alive, the six-foot-eight-inch Kitty Rotolo, recently convicted of swiping a $40,000 Hindu goddess of compassion from a Village antiques store. She also interviews a sad-faced upstate trans woman who is plainly terrified to say what she knows. Over the phone, a retired detective who sounds like a guy out of a B movie says that Cruz is dealing with more powerful forces than she knows. “Don’t play detective,” he warns her. “Leave this to the people that should handle it.” He declines to supply a for instance.

As a fan of formula mystery-thrillers in print, movies, and on TV, I’m struck by the frequency of plots centering on cops who doggedly pursue cold cases — often defying their superiors’ orders and losing their jobs when they step on important people’s toes. It doesn’t matter, you see, because they just can’t live with injustice. This idea does not seem to be in effect in Manhattan’s 6th Precinct, which oversees the West Village and the Hudson piers near where Johnson’s body was found. Cruz has a list of people they should interview, although they won’t, they never will. Perhaps it’s that in some circles, people like Marsha P. Johnson and Islan Nettles are not seen as fully human, so why waste valuable resources?

It’s not clear exactly what happened to Marsha P. Johnson on July 4 or 5, 1992. The autopsy report obtained by Cruz (with the help of Johnson’s family in New Jersey) raises a number of possibilities. On index cards, Cruz prints several of them: “Suicide,” “Accident,” “Dirty Cop,” and “Mob.” Names are named. I hope the film inspires a new generation of amateur sleuths. Maybe — thanks to movies like The Death and Life of Marsha P. Johnson — a wish-fulfilling fictional scenario will come to pass in the real world, and the injustices of history will stand plainly in the living

present.