Peter Landesman’s docudrama Parkland isn’t likely to contribute significantly to the enduring and heated debates about who, or what, was responsible for the assassination of President John F. Kennedy. As the half-century anniversary of the event approaches, Parkland may be timely but it’s unlikely to engender much additional controversy. Landesman and his movie are concerned with the immediate aftermath in Dallas of the assassination, not in the politics or the history of the various investigations and conspiracy theories.

Landesman is no Oliver Stone and Parkland is nothing like director Stone’s famously lurid and reckless JFK, with its demagogic tale of plots and cabals. (Stone went so far as to raise the possibility of complicity by Vice President Lyndon B. Johnson.) Landesman isn’t interested in single-shooter, single-bullet, and grassy-knoll arguments. Rather, he has tried to depict the initial impacts of the crime on several actual people, and the shock, fear, and turmoil that gripped Dallas in its wake. Adapted by Landesman from the book Four Days in Dallas by Vincent Bugliosi, Parkland succeeds much of the time in persuasively recreating those reactions.

The characters portrayed include Dallas Secret Service chief Forrest Sorrels (Billy Bob Thornton); women’s wear manufacturer Abraham Zapruder (Paul Giamatti), whose famous home movie of the murder became indispensable evidence perennially fought over by pro- and anti-conspiracy theorists; and Dallas FBI Agent James Hosty (Ron Livingston), whose caseload included the man widely held to be the perpetrator, Lee Harvey Oswald, and who has confessed to being a party to a subsidiary cover-up. There are also Oswald’s admirable brother Robert (James Badge Dale) and his delusionally self-dramatizing mother (Aussie actress Jacki Weaver, in an expert performance that repels even as it fascinates).

Landesman doesn’t quite manage to consistently sustain his film’s pace and cohesion. There are a lot of incidents and people to coordinate, and he hasn’t always made the best use of them. The grim, harrowing scenes in Dallas’s Parkland Hospital, where Kennedy was rushed, are riveting, but afterward there are a few lapses and slackening. And there’s a very noticeable absence: Oswald’s killer, Jack Ruby, a crucial and remarkable participant. Parkland covers Ruby’s deadly intervention but leaves him out of things.

At little more than an hour and a half in length, Parkland, Landesman’s debut as a feature director, could have depicted things a little more effectively. But it’s often compelling and an honorable effort.

Watch the trailer for Parkland