Parkland

Pick your favourite conspiracy theory: Magic Bullet, Executive Order 11110, Lyndon B Johnson, the Mafia, a UFO cover-up, the Illuminati, George Bush Sr, Richard Nixon, the Israelis, the KGB, gay thrill-seeker David Ferrie, the CIA or possibly all of the above.

Just when you think there's no rock left unturned by JFKologists, along comes this affecting folk history. Based on a book by Manson Family prosecutor Vincent Bugliosi, Parkland forms a daisy-chain between the lesser-seen parties present in Dallas on November 22nd, 1963.

Much of the film's focus is trained on Parkland Hospital, the facility where John F Kennedy was pronounced dead. There is a marked difference in the dogged, tearful determination of staff – including Zac Efron's young Dr Carrico and Marcia Gay Harden's Head Nurse – in their battle to save the president, compared to their subdued, less frantic efforts when Lee Harvey Oswald arrives in the same ER some hours later.

There are fascinating, previously overlooked historic details, including the political (and literal) punch-up between federal and local authorities over Kennedy's body. At its best, this chorus of voices allows for a humanity that is frequently eclipsed by the meta-narratives. There are beautifully turned performances, such as James Badge Dale's Robert Oswald (Lee's stricken brother). Paul Giamatti's Abraham Zapruder reminds us of a time before gruesome frontline footage. Ron Livingston deftly turns up the panic as FBI fall guy James P Hosty. And just when you think that Jacki Weaver has delivered an Americanised version of Animal Kingdom's monstrous matriarch, she breaks down and transforms Marguerite Oswald into a devastated, grieving mommy.

Director Peter Landesman and cinematographer Barry Ackroyd (Ken Loach's regular) keep the camera and crosscuts moving; Parkland is animated by a taut, immediate naturalism. In keeping with the film's grassroots focus, the revelations are unshowy, the emotional clout is stealthy, and JFKologists can rest easy knowing that the project neither engages with nor contradicts their pet preoccupations.