If you come into Brian De Palma’s The Untouchables expecting a history lesson, well, that’s your fault. In no way is this an accurate portrayal of treasury officer Eliot Ness and his showdown with the volcanic, tax-evading sociopath mobster Al Capone; what it is is a magnificent cops and robbers fable whose romanticism has only grown more endearing over the last thirty years.

With the razor-sharp, melodramatic score from the incomparable maestro Ennio Morricone, tapping into a certain urgency when needed, the prickly screenplay from the master, David Mamet, the slick cinematography, terrific suspense, and a cast who seemed to be born for their respective roles at the time, The Untouchables whisks along on its substantial merits, leaving all historical accuracy behind in lieu of a rich bit of pulp storytelling that makes it one of the best of all gangster films. And in 1987, this sort of story felt alien.

The mid 80s was a bit of a void for the gangster genre. Save for De Palma’s other gangster opus, Scarface in 1983, the genre had seen a significant ebb in the midst of Reagan’s “Morning in America” hedonism. A look back at the crooks and thieves of America’s past wasn’t in vogue, and The Untouchables represented a distant era of the country that hadn’t been explored during the decade. But De Palma delivered the goods, and his film was noticed; and as the decades tick away, the idiosyncratic style De Palma employs here has become both a relic and a flashpoint of a certain type of crime drama we may never see again.

Sean Connery’s Jim Malone has always gotten the bulk of praise, and rightfully so because his character is the most magnanimous of the group. Connery knows how to deliver David Mamet’s words with a certain extra bit of juice – the scene inside the church is one of the best of the entire genre thanks to the urgency in his cadence. But The Untouchables wouldn’t be near as captivating were it not for the blank-slate performances of Kevin Costner as Eliot Ness. Costner’s dry, deliberately wooden performance as the Boy Scout treasury officer grounds the entire story in reality. As the cops and robbers shoot-em-up elements spiral up and out around him, De Palma’s camera flourishes brilliantly, and Mamet’s screenplay embellishes at every turn, it’s Costner’s flat delivery and dry vocal chords that keep the story centered.

The rest of the cast is just as perfect as Connery and Costner. Robert De Niro, who seems to be working with his own set of rules, adds a specter of menace as Al Capone. He may only have a few moments to shine – namely the baseball bat scene in the middle of the second act – but his presence looms large. He is more of a mythological beast come to life as his performance is exclusive from the center of the story, but the distance works. Andy Garcia is perfectly prickly as Stone, and Charles Martin Smith handles the unfortunate duties of “First to Die” team member, Oscar.

For all its pomp and circumstance at the time, The Untouchables has managed to sing even louder and sharper in this, it’s thirtieth year. It has all the familiar De Palma style flourishes, but remains a classic tale of cops and crooks, told less as a true story and more as a fable of pulp fiction, handed down through generations of kids who remember Eliot Ness wiping the streets clean of crime during the prohibition. De Palma captures the mysticism of these unflappable lawmen, dedicated to justice and unflinching in the face of danger. The purity of this story feels wholly unfamiliar when compared to the De Palma catalogue, full of rogues and murderers. But he manages to hit all the right beats to romanticize a bygone era in both cinema and American history.

De Palma’s action set pieces still work beautifully, for all their flaws. The shootout at the Canada border, the showdown between Ness and Frank Nitti (Billy Drago) on the rooftop, the Battleship Potemkin homage on the staircase in Grand Central and, most tragically, Nitti’s visit to Malone’s apartment… they all sing with the terrific choreography of a master at the top of his craft.

The immediate play would be to compare The Untouchables to the classic gangster films. How does it stack up against the likes of White Heat? The Godfather? Goodfellas? Maybe it isn’t as seamless or classic as some of the best of the genre – and for my money Carlito’s Way is the better De Palma entry into this field – but something about The Untouchables feels more timeless than just about any of the greats. Perhaps it’s the effervescent approach to the story, or Mamet’s killer words, or the impeccable casting that give the film a timeless quality. Whatever the case, the story has only gotten more potent and more captivating over the last thirty years.

Perhaps The Untouchables is a classic because of its flaws rather than in spite of them.