The assassination of John F. Kennedy has been covered in many forms—in the case of film, there have been documentaries, dramatizations, and (as in the case of Oliver Stone’s picture) conspiracy potboilers. This being the fiftieth anniversary of the event, one can expect a larger number of them than usual, among which Peter Landesman takes the staid docu-drama approach in “Parkland,” titled after the Dallas hospital where the president was taken for treatment (and where, of course, Lee Harvey Oswald was also futilely operated on after he was shot by Jack Ruby). Basing his script on the initial section of Vincent Bugliosi’s book about the tragedy as well as his own researches, Landesman, a former journalist, concentrates on the individuals on the fringes of history—Abraham Zapruder (the businessman who took the famous 8mm footage of the assassination), the doctors and nurses in the Parkland emergency room, the traumatized secret service agents, Kennedy aides and local FBI agents, as well as Oswald’s wacky mother Marguerite and his straight-arrow brother Robert. The main figures—Kennedy, Jackie, Lyndon Johnson, Lee Oswald—appear briefly, in both news footage and recreated scenes. But they’re not stage center, and the faces of the actors playing them are usually obscured or seen in fleeting glances (partially because the actors aren’t always exact matches to figures we all recognize).

What Landesman wants to capture is the chaotic swirl of action around the assassination, rather than the assassination itself. That’s a plausible way to provide a new slant on the event, and in truth “Parkland” is compulsively watchable because it delves into the byways of history. But despite a certain homely integrity that derives in part from the fact that it obviously tries to do much on an obviously limited budget, the film comes across as a little tacky, and some will even see it, fairly or not, as exploitative.

The main threads of the narrative begin with the drama inside the hospital, where young surgeons Jim Carrico (Zac Efron) and Malcolm Perry (Colin Hanks), assisted by no-nonsense nurse Doris Nelson (Marcia Gay Harden), work desperately to save the President as aides like Kenneth O’Donnell (Mark Duplass) and agents like Roy Kellerman (Tom Welling) hover in the background, stunned; eventually a priest (Jackie Earle Haley) is brought in to administer the last rites. Simultaneously Zapruder (Paul Giamatti) is approached by head Secret Service agent Forrest Sorrels (Billy Bob Thornton) to secure control over the 8mm film the businessman took of the shooting, which must be hurriedly processed at a local facility.

At the local FBI office, the division chief (David Harbour) discovers that one of his agents, James Hosty (Ron Livingston) had investigated accused assassin Lee Harvey Oswald (Jeremy Strong) but failed to follow up even after receiving a threatening note from him. The revelation sends the office into a tailspin and leads to a suggestion to bury the offending evidence. And Oswald’s brother Robert (James Badge Dale) must deal not only with the charges lodged against his brother but the ravings of their wacky mother Marguerite (Jacki Weaver), who insists that her son was a US agent while jockeying for press coverage.

In fastening on these strands of the story, Landesman has obviously chosen to leave out many people (Governor John Connolly, for example), and a great many facts. But at the same time the approach allows him to concentrate on telling details that are generally unknown, from the struggle that ensues between Kellerman and the Dallas County Medical Examiner over the disposition of Kennedy’s body and the difficulty in fitting the coffin containing it onto Air Force One, to Zapruder’s agonizing decision about selling his film to a media outlet he could trust to follow limitations he wanted to put on its use and the need for Robert Oswald to plead with reporters to act as pallbearers at his brother’s gravesite. To provide context to its limited perspective on the event, the picture utilizes familiar archival footage—of Kennedy’s arrival in Dallas and the ensuing motorcade, of Walter Cronkite announcing the President’s death. It’s an understandable tactic, but one that can create a jarring effect in the juxtaposition between the real and the recreated.

Some parts of “Parkland” work better than others. Ironically, the best section is that dealing with the Oswalds, simply because Weaver and Dale offer such commanding performances. The weakest is the emergency room material, not only because the casting in it doesn’t quite work, though all the actors certainly try, but because the splashes of blood and gore are so profuse—something that shows the film’s refusal to be simply reverential but at the same time will strike many as excessive. In between are the Zapruder elements, dominated by Giamatti’s highly charged turn and Thornton’s tight-lipped solemnity, and the FBI sequences, which represent the closest Landesman comes to playing to the conspiracy crowd, although even here it holds back.

Overall one has to admire “Parkland” for its sincerity, sobriety and dedication to faithful recreation (kudos to production designer Bruce Curtis, art director Rodney Becker, and costume designer Kari Perkins, with cinematographer Barry Ackroyd making reasonably good use of some obviously inhospitable locations). While in the end it can’t help but seem a bit like a pageant in which mostly recognizable faces pass by posing as real people—the effect isn’t unlike the misguided star cameos George Stevens inserted into “The Greatest Story Ever Told,” and it’s amplified by James Newton Howard’s sometimes throbbing, sometimes blaring score— the material is fascinating enough to keep one watching. To some, the fascination the film evokes will seem morbid and sensationalistic. To others, it will instead represent the result of an honest effort to disclose another side to a tragic event that people don’t really know as well as they might think they do. And at the very least, it doesn’t falsify or speculate—as so many of the other takes on this subject have done.