The assassination of JFK has been poked, prodded and pulled in every possible direction over the past five decades — and lo, people still speculate about this conspiracy or that regarding the tragic event — but Peter Landesman's "Parkland" aims to explore a few new perspectives on the day everyone then-alive has his or her own story about.

The film chronicles the moments leading up to, during and especially after John F. Kennedy was shot in his open-top limo in Dallas and lays focus upon the staff of Dallas Parkland Hospital, the facility which the Prez was immediately transported to and ultimately pronounced dead at just thirty minutes after the fateful shooting.

As this first trailer for the film shows, Zac Efron puts on a shirt and some of that stellar emotional range of his ...

... to portray the young doctor suddenly strapped with the duty of treating the POTUS in his very gravest hour.

Meanwhile, the movie also spotlights Paul Giamatti's Abraham Zapruder, the guy who inadvertently captured the most famous home video of all time, and Billy Bob Thornton's Secret Service agent Forrest Sorrels who comes to collect the reel for use in the Warren Commission's investigation. Also of interest is a look at the FBI agents who'd been eyeing Lee Harvey Oswald for his communist views long before he'd shot JFK but did not report him to the Secret Service.

Marcia Gay Harden, Tom Welling, Ron Livingston, Jackie Earle Haley and Colin Hanks also star in "Parkland," which is expected to hit theaters Sept. 20.