Surveillance footage showing Michael Brown in a Ferguson, Missouri market on the day he was fatally shot was heavily edited by a documentary crew and is “100 percent false,” an attorney for the convenience store told reporters Monday.

A documentary shown at film festival South by Southwest in Austin, Texas suggests that Brown traded a bag of marijuana for the cigarillos he was alleged to have stolen. It claims he left them behind on the counter and came back to pick them up the day he allegedly robbed the store. Filmmaker Jason Pollock states, "Mike did not rob the store."

Attorney Jay Kanzler said the interaction shown in the film was edited down from 4 minutes to 30 seconds and disputes the claims made by filmmaker Jason Pollock.

The unedited surveillance footage appears to show store clerks rejecting Brown’s offer of marijuana in exchange for sodas and cigarillos.

The footage, which was shown from four different angles, shows Brown leaving the store with the marijuana and leaving sodas and cigarillos behind on the counter. Clerks were seen putting the items back before closing.

“The entire story is preposterous and laughable,” said Kanzler. “(The filmmaker) owes an apology to the store owner, the community of Ferguson, and the police officers who put their lives on the line because of his recklessness.”

St. Louis County prosecutor Bob McCulloch said the police had the same video and that the footage “is not new, not a surprise and not relevant.”

McCulloch told reporters the reason they did not release the footage was because it was not relevant to the case.

About 100 protesters gathered outside the store Sunday night in response to the documentary. The St. Louis Post-Dispatch reports that seven or eight shots were heard, but no injuries reported. Police arrested some protesters and cleared the scene when the market closed.

Prosecutors on Monday charged a St. Louis man with trying to set a Ferguson police car on fire during the protests. Police say Henry Stokes, 44, put a napkin in the gas tank opening of the police car and tried to use a lighter to set it aflame, but fled when police saw him.

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Fox News' Jason M. Kopp andThe Associated Press contributed to this report.