{{show_title_date || "Police release footage showing moments before shooting on Michael Brown anniversary, 8/11/15, 8:49 PM ET"}}

Police release video showing moments before Ferguson shooting

Updated

Police on Tuesday released surveillance video that they say shows a teenager appear to pull a weapon from his waistband before he was later shot and critically wounded by plainclothes police in Ferguson, Missouri.

The shooting of Tyrone Harris, 18, Sunday, on the anniversary of the death of Michael Brown, threatened to reignite racial tensions in the city that exploded in unrest after last year’s deadly shooting by a white police officer.

Harris is in critical condition. He is charged with four counts of assault on law enforcement, five counts of armed criminal action and one count of shooting at a motor vehicle.

The surveillance video, given to police by a local business, shows a panicked crowd running for cover and then a young man in a white T-shirt appearing to be holding a gun running off screen and pointing the weapon. Police identified that man as Harris. The video appears to dispute some recent reports and witnesses who said Harris was not armed.

St. Louis County authorities declared a state of emergency Monday after Sunday’s violence. St. Louis County Police Chief Jon Belmar said the police shooting took place after two separate groups in the vicinity had traded a “remarkable” amount of gunfire — between 40 and 50 shots. He said those involved were “criminals, not protesters” marking the anniversary of Brown’s death.

RELATED: Dozens of arrests in Ferguson amid protests

More than 100 people have been arrested in demonstrations so far, authorities said.

Police said a Harris opened fire on the officers, who were in an unmarked car, and the officers gave chase on foot. Harris was shot after he allegedly fired a stolen 9mm handgun at the officers, who returned fire, police said.

The four plainclothes police officers involved have been placed on administrative leave.

This article originally appeared on NBCNews.com.

Ferguson, Michael Brown and Missouri

Police release video showing moments before Ferguson shooting

Updated