VENICE – As we near the 50th anniversary of John F. Kennedy’s assassination, it’s comforting to know that he died surrounded by so many attractive people. Cold comfort, admittedly, if indeed we still require any consolation at all for a moment in history that, however rupturing, has by now been amply processed — both on screen and elsewhere.

But it’s pretty much all I gained from Peter Landesman’s vapidly exploitative take on the events of November 22, 1963, as experienced by the sundry agents, doctors, servicemen and civilians who played a tangential but first-hand role in the unhappy day. Like Emilio Estevez’s similar but marginally more redeemable “Bobby,” it reveals nothing about the tragedy that you didn’t already know, bar that which you certainly never needed to know in the first place. “Hey, there’s Jackie! I think so, at any rate: looks nothing like her. Anyway, how did the nurse feel about it all?” 

Writer-director Peter Landesman — a practised journalist demonstrating few of his erstwhile profession’s best principles in his debut feature — adapted his fidgety screenplay from Vincent Bugliosi’s 700-page investigative tome “Four Days in November.” Apart from the name and place captions cluttering the screen in its opening stretches, however, the film doesn’t give the impression of being all that thoroughly researched, as various stunned characters trade stock movie dialogue to convey their unsurprising anguish. “This is the first time the Secret Service has lost a president under its watch,” barks an officious senior suit, a banal line that accidentally hits at least one human truth: in the immediate fallout of a major figure’s passing, it is the first instinct of many to make it all about themselves.

As such, “Parkland” is structured a little like a hypothetical 1963 Twitter timeline, narrowed by the hashtag #JFKRIP: none of the participants have much to say about the man or his absence, but they’re appropriately sad about it. Zac Efron’s dreamy ER medic Jim Carrico’s lip quivers, dreamily, as he realizes the futility of the resuscitators he’s dreamily applying to the President’s chest, but keeps dreamily pumping away regardless, jaw clenched in dreamy despair. Paul Giamatti’s humble civilian Abraham Zapruder frets humbly about the in-demand Super 8 footage of the assassination he’s accidentally (but humbly) captured, humbly calling on media vultures to Do The Right Thing. Ron Livingston’s stricken FBI agent James Hosty looks stricken as he ponders the striking possibility that he let Lee Harvey Oswald slip through his fingers, and is further stricken as his superiors chastise him for his neglect. Meanwhile, an unrecognizable Jackie Kennedy (Kat Steffens) shows up to shed a few wordless tears in a recognizable pink suit, before beating a hasty retreat from the tacky proceedings.

Such is the level of characterization and emotional profundity throughout: rather a severe shortcoming in a film that purports to tell the story mostly through the eyes of the real, little people. It’s understandable that writers and actors often feel hamstrung when required to make a living, breathing character of a celebrity figure as iconic as, say, John F. Kennedy — whose face here is coyly shielded at every turn. But even in a project of such dubious taste, the regular-folk construct should be an avenue toward portraying textbook history in an empathetically human context, not gawking at the second-degree famousness of someone who once got to touch the President’s bloodied corpse. (Landesman’s script misses even the small sociological details: how likely is it that a cadre of iron-jawed presidential aides would have addressed the newly widowed First Lady by her abbreviated Christian name?)  

The only figure in this waxen ensemble who emerges as something resembling a complex, conflicted human being is Oswald’s decent, stoic but tacitly ashamed brother Robert, a man in no doubt as to his sibling’s guilt but attempting to muster up enough unconditional love to understand his mindset. In the only performance here that feels porous and palpably damaged, James Badge Dale is given too little to work with to come close to salvaging the whole tawdry affair, but his efforts are appreciated all the same. As his vindictive mother Marguerite, meanwhile, Jacki Weaver goes to the opposite extreme, playing the woman’s horn-rimmed glare and hissing conspiracy theories for high camp value. It’s the cartoonish approach this material arguably calls for, but a distracting one when none of her blander co-stars apparently received the memo.

Shot by the great Barry Ackroyd in a curious fashion that suggests Landesman was at once after un-anchored, “United 93”-style immediacy and lacquered period warmth, the film cuts urgently from strand to strand without amassing much in the way of momentum — largely because the human stakes across the ensemble are so uniform. “The Grown-Ups,” a wonderful episode from the third season of AMC’s “Mad Men” (directed, as it happens, by Oscar nominee Barbet Schroeder) got right pretty much everything that “Parkland” gets wrong in trying to dramatize the repercussions of Kennedy’s death as felt by those outside the inner circle, the eerie emptiness of mourning someone you don’t know — all without feeling the need to get within even six degrees of separation from the man himself.

Landesman, by contrast, milks even the most insignificant first-hand minutiae for pathos, bottoming out by showing us several brick-faced servicemen struggling to maneuver Kennedy’s coffin through a narrow airplane door. It’s an obliviously grotesque scene, made even more obliviously hilarious as James Newton Howard’s cloth-eared score swells over their huffing and puffing, vainly attempting to ennoble a process that is the political equivalent of pushing a sofa up a stairwell: “An undignified end for a dignified man,” to crib a line from Giamatti’s fussy turn. That “Parkland” opens on October 4 — somehow skipping out on the Golden Anniversary date only seven weeks later — may be its solitary act of good taste.