Naperville police said during a protest on June 1, someone threw multiple explosive devices, causing minor injuries to several officers.
Christian Rea, 19, is charged with civil unrest in the incident. Federal investigators allege Rea threw the device, injuring the officers and causing panic in the crowd. He was arrested Thursday morning and appeared in court the same day.
RELATED: Naperville protests video shows explosion that injured several police officers
On June 1 a large crowd gathered in Naperville for a peaceful protest in which the police chief knelt in solidarity with demonstrators.
But just after 10 p.m., large crowds were reported near Aurora and Main Street. According to witnesses, outside groups pulled up and damaged multiple businesses in downtown. One witness said a restaurant and a jewelry store had its windows smashed.
RELATED: Downtown Naperville looting leaves businesses damaged
During ABC7's 10 p.m. newscast, the crew on the scene reported hearing a group say "let's start looting" before trying to kick open the doors at a Walgreens just off Main Street.
A SWAT Team was called to the Walgreens after a group of people threw rocks and caused damage to the building, police said.