Just about the sixth time we cut back to the same photograph — a smiling Nicky Barnes, wearing shades, taken during a party in Harlem while he was one of the neighborhood’s reigning cocaine chieftans — it’s impossible not to wonder how the documentary “Mr. Untouchable” ever made its way into a final cut, much less into a movie theater. Here is a movie with so little original source material, so little insight into its principal personalities, and so little insider information about the most important details of their lives, that it seems we are returned to the same handful of photos and the same grainy, archival B-roll repeatedly. In the end, it has the feel of a 20-minute snapshot of a fascinating, infuriating figure.

That said, there’s no question why the documentary is hitting theaters now, a week ahead of next Friday’s Oscar heavyweight, “American Gangster,” about Frank Lucas’s Harlem heroin empire. During one high-energy sequence in that fictionalized film, a smiling, sneering Cuba Gooding Jr., playing Barnes, struts into one of his Harlem clubs, just as a gathered crowd of admirers holds up copies of the New York Times Magazine. There, on the cover, is a photo for which Barnes posed, and the headline of that weekend’s cover story: “Mr. Untouchable.”

We learn in Marc Levin’s documentary that Barnes’s decision to pose for this photo — his attorney goes on to explain it was better than having the Times use a mug shot — was seen as an act of such arrogance that President Carter himself took note, issuing personal orders that derailing this pusher and his thriving cocaine business was to be considered a national priority. It is the iconic, “you can’t touch me” taunt, one that reeks of a man too bold and too flawed, that seems ripe for analysis — an analysis that “Mr. Untouchable” seems incapable of undertaking.

The documentary is big on superficiality and low on scrutiny, and that shallowness leads to confused conclusions. For a majority of the movie, Barnes seems to be celebrated and revered, his freewheeling days giving the documentary its pulse and pep. It isn’t until the midpoint that a drug enforcement official suggests the idea that Barnes’s exciting lifestyle was only made possible through destroying the Harlem community he claimed to be serving. Just as he was dressing up as Santa Claus and handing out free turkeys at Christmas, and spreading the wealth among the local men who worked for him, Barnes was addicting, overcharging, and abandoning a growing number of customers, who were left to rot in the gutter.

This idea of manipulator-as-savior is a complicated one, worthy of a feature film — hence the raging inner conflict apparent in “American Gangster” — but it goes undeveloped by Mr. Levin almost from the beginning. For starters, the documentary’s opening segments, steeped in sensationalism, brush over Barnes’s violent childhood as if it were irrelevant. Then it plows headfirst into his heyday while ignoring the socioeconomic forces underway that gave men like Barnes and Lucas an opening to recruit a frustrated workforce as employees and customers.

But very little is gained from Mr. Levin’s central interview with Barnes, who, due to threats on his life, never appears in the film. His visage is obscured by shadows and by Mr. Levin pointing the camera away from his face entirely, looking instead at his gesturing hands or his jewelry. What’s clear is that he has no remorse for anything he’s done, and that he is almost celebratory that he was able to take revenge on those confidants who betrayed him. Here he is, Barnes says from the shadows as the music swells, out in the free world, while they rot in prison.

Using the same title as the one that appeared in the New York Times Magazine, “Mr. Untouchable” fails in adding anything substantial to the record, other than a misplaced dose of nostalgia for a dark time and a bizarre bit of admiration for a despicable character. After 92 minutes, Nicky Barnes seems as distant a figure as ever and the greatest irony is that, after all this, “Mr. Untouchable” remains beyond our grasp.

ssnyder@nysun.com