The assassination thriller ''Vantage Point'' might have been a triumph of form over content, technique over substance, if only there were anything worthy about its form or technique.

This preposterous yarn relies on a quickly strained gimmick - showing the shooting of the U.S. president over and over from different characters' viewpoints - to cover up the fact that it's less a story than a commotion of human pool balls clattering against one another in ways that defy sense and even physics. The gimmick must have looked good on the page. The filmmakers rounded up a superb cast that includes Dennis Quaid and Matthew Fox as Secret Service agents, Sigourney Weaver as a TV news producer, William Hurt as the president and Forest Whitaker as a tourist whose video recording stands as the modern equivalent of the Zapruder film.

All the actors star in their own little part of the tale, which repeats itself like a bad burrito, each segment tossing off bland revelations and cliffhangers that gradually spell out the absurd machinations setting things in motion. The shallow back-story in first-time screenwriter Barry L. Levy's script is this: President Ashton (Hurt) and world leaders have converged on Salamanca, Spain, for a historic summit to fight terrorism.

Stepping to the podium in a crowded city square, Ashton is shot twice. Moments later, a huge explosion is heard nearby. A few minutes after that, a bomb blast decimates the square. That leaves Thomas Barnes (Quaid) - a Secret Service agent who took a bullet for the president a year earlier - and partner Kent Taylor (Fox) rushing around to figure out what happened. Barnes reviews footage shot by American tourist Howard Lewis (Whitaker) and a TV network whose mobile studio is overseen by producer Rex Brooks (Weaver). Viewed by Barnes in a matter of seconds, their footage conveniently has all the clues he needs to put him on the heels of a key instigator. Other principles include a Salamanca cop (Eduardo Noriega), his girlfriend (Ayelet Zurer), a friendly mystery man (Said Taghmaoui) and a Spanish special-services soldier (Edgar Ramirez).

Director Pete Travis made a terrific debut with 2004's ''Omagh,'' a compassionate, understated drama about a Northern Ireland terrorist bombing and its aftermath. It's a surprising disappointment that he should follow that rich, restrained story with a loud, surging mess such as ''Vantage Point.'' Characters race after cars on foot and not only keep pace, but occasionally gain ground. During a frenzied vehicle chase, one driver recognizes another from the tiniest fraction-of-a-second glimpse in a rearview mirror, through tinted glass, at a distance of several dozen yards.

Worst of all, the same handful of people - from the president down to a little girl who lost her ice cream cone - keep impossibly colliding amid the chaos, reducing the thousands of others rushing about in confusion to mere human white noise. At first, it's annoying as the action rewinds every 15 minutes or so to play things back from another perspective. The ham-fisted manner in which the filmmakers present those transitions eventually becomes laughable, as do the outrageous plot twists.

The pace is so frantic that viewers cannot anchor on to any of the characters, and the performers are stuck repeating empty dialogue amounting to filler as we wait for the same gunshots, explosions and chases to happen again. There's no point to any of this. No insights on terrorism, no commentary about foreign policy, no human drama. ''Vantage Point'' is a rotten action flick dressed up in artifice and pretension.

If the overseers of ''24'' had made an episode this bad, they would have immediately switched to Daylight Savings Time to leap ahead an hour and skip over it.

- More 'Vantage Point' pictures here

By DAVID GERMAIN AP Movie Writer

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