The incident took place on Thursday, the U.S. Thanksgiving holiday, when police approached a 29-year-old man drinking alcohol in the afternoon at a bus stop on Chicago’s South Side, CBS News reported. “While a single video does not depict the entirety of the interactions between the police and the individual, this particular video is very disturbing,” Lightfoot wrote in a post on Twitter. The Civilian Office of Police Accountability, a city oversight body, was investigating, she said.