Chicago Police Department officers showed footage Monday of last weekend’s attack on a statue of Christopher Columbus in the city, in which rioters armed with projectiles used “peaceful” protests as a cover for attacks on police.

The footage of the attack, revealed to the media by Superintendent David Brown, showed a peaceful procession marching behind banners suspended from PVC pipe, emblazoned with “Black Lives Matter,” “Defund the Police,” and other slogans.

Upon reaching Grant Park, the banners were used to shield a group of rioters who prepared to ambush police, putting up umbrellas, preparing projectiles and changing into black clothing. The “peaceful” protesters appeared to move in front of the rioters deliberately, to shield them from the view of the police officers guarding the Columbus statue nearby.

The rioters then moved in what police described as “a platoon-like fashion” toward the statue, using the protest banners as cover. The PVC pipe was then removed from the banners and sharpened into weapons to be used against police officers. Rioters distributed “weapons” — projectiles such as rocks, frozen cans, and frozen water bottles — throughout the crowd. They also restocked the weapons throughout the confrontation with police, distributing them from shopping carts.

The rioters then pelted the officers with projectiles, and hit them with PVC pipes. Forty-nine officers suffered injuries in the confrontation, including concussions; one suffered a severe eye injury when he was hit by an incendiary or explosive device that detonated near his eye as he stood near the statue; that officer may eventually require surgery, police said.

Grant Park was made famous on Election Night in 2008, where it was the site of President-elect Barack Obama’s victory rally.

Superintendent Brown, who formerly led the Dallas Police Department, achieved national recognition in 2016, when five police officers in Dallas were assassinated by a sniper during a Black Lives Matter protest.

Brown emphasized that diverting police resources to protests “puts lives at risk on our South and West sides,” the largely African American areas of the city in which murders and gang violence are typically at their most intense.

“Now we must assume that there may be mobs working with peaceful protesters to inflict violence,” Brown said.

Asked whether the protest organizers were aware that violent individuals intended to use the peaceful demonstration to attack police, Superintendent Brown said: “God, I hope not. But it sure looks like it.”

Chicago Mayor Lori Lightfoot rejected President Donald Trump’s attempt to offer federal law enforcement resources to the city on Tuesday. “Under no circumstances will I allow Donald Trump’s troops to come to Chicago and terrorize our residents,” she tweeted on Tuesday.

Shortly thereafter, news broke of a mass shooting at a Chicago funeral home, in which 14 were injured.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News and the host of Breitbart News Sunday on Sirius XM Patriot on Sunday evenings from 7 p.m. to 10 p.m. ET (4 p.m. to 7 p.m. PT). His new book, RED NOVEMBER, tells the story of the 2020 Democratic presidential primary from a conservative perspective. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. Follow him on Twitter at @joelpollak.

Correction: the footage was released Monday, not Tuesday.