Police in Chicago arrested more than 100 people on Sunday and Monday following a police shooting and subsequent looting, according to NBC News. 

Mayor Lori Lightfoot and Police Superintendent David Brown held a press conference Monday morning to explain what happened, telling reporters that hundreds of people began looting stores in the city because of a misunderstanding about an earlier incident involving a 20-year-old who was shot by police, reports ABC 7. 

Lightfoot and Brown explained that on Sunday, someone called the police in Englewood about a man with a gun. When police arrived, the man began to shoot at the officers, ABC 7 reported. The officers returned fire and struck the 20-year-old. According to Brown, the young man is in stable condition at the University of Chicago Hospital.

Brown went on to explain that police began to see misinformation online that he believes stoked anger and led to the looting.

Photos from the scene of the initial shooting show people lined up in front of dozens of police officers, who eventually left the area after demands from local residents. 

During the press conference, Brown said people were lying about the 20-year-old's age, calling him a teenager and stoking outrage about the shooting despite officers believing it was justified. 

Police officials said some social media accounts were sharing claims that the officers shot a 15-year-old boy, and Brown added that "tempers flared, fueled by misinformation."

People later began to smash windows, throw projectiles at officers and enter stores, according to Brown. 

"This wasn't an organized protest. It was an incident of pure criminality. Criminals took to streets with confidence that there would be no consequences for their actions. I refuse to let these cowardly acts hold our city hostage," Brown said.

He added that the officers involved in the shooting of the 20-year-old have been placed on administrative duty but that the man had been previously arrested four times for burglary, child endangerment and domestic battery.

By midnight, the crowds had gotten out of control. Multiple videos show hundreds of people taking things from stores, and Brown said officers were shot at while trying to arrest a man carrying a cash register. 

"These were not poor people engaged in petty theft to feed themselves and their families. This was straight-up felony criminal conduct," Mayor Lightfoot said during the press conference. 

"I don't care, I do not care, whatever justification was given for this. There is no justification for criminal behavior, ever. You have no right to take and destroy the property of others. Our residents deserve to be safe," she said. 

Police were forced to shut down streets in Chicago's Loop and stop the city's bus and train services. There was also looting reported in River North, Streeterville, Lincoln Park, the Gold Coast and the South Loop, according to NBC Chicago. 

Stores like Saks Fifth Avenue and Coach were looted along Michigan Avenue, according to police. 

"To those engaged in criminal behavior — let's be clear — we are coming for you. I don't care what justification is given, there is no justification for criminal behavior," Lightfoot said.

"Our citizens deserve to be safe. Our officers deserve to be able to do their job without having to worry about shots fired," Lightfoot said. 

Police eventually arrested more than 100 people who were accused or caught on camera looting, shooting and causing chaos after midnight. The Chicago Tribune reported that cars were dropping people off near stores that were looted. 

Cook County State’s Attorney Kim Foxx faced criticism from Republican officials, conservative state lawmakers and news reporters who tried to tie the Sunday night mayhem to her decision to dismiss all misdemeanor charges related to the recent protests over George Floyd's killing. 

Community members came out on Monday morning to help clean up the damage. 

Some local lawmakers called for the National Guard to be sent in, but Gov. J.B. Pritzker denied the request.