The incident occurred at his office at 54th Street and Wentworth Avenue on June 1 before sunrise. Rush said his office was burglarized and afterward they discovered video of the officers in his office on their cell phones, relaxing, lounging, sleeping and eating.
"They even had the unmitigated gall to make coffee for themselves and to pop popcorn, my popcorn, in my microwave while looters were tearing apart businesses. Within their sight and within their reach," Rush said.
Three supervisors and 10 officers were captured on the video, and spent several hours in the office.
WATCH: Raw video of police officers in Rep. Rush's office
Rush went to the mayor with the video this week. Mayor Lori Lightfoot and Chicago Police Superintendent David Brown said all of them will face disciplinary action.
"These individuals did indeed abandon their responsibilities and their obligation and their oath to serve and protect," Mayor Lightfoot said. "We should all be disgusted."
"We have to reveal our leadership. If that means strict discipline, that's what it means. We are determined," said Brown.
Lightfoot said there was a core group of officers in the office and then several others coming in and out. She said at its height, there were 13 officers. She offered an apology on behalf of the city.
"It is a personal embarrassment to me," Lightfoot said.
Police officials agreed.
"I've been a policeman for 34 years and I've never been as embarrassed as I am right now," said Chief of Patrol Fred Waller.
The involvement of three supervisors is even more disturbing to the mayor and superintendent, as it casts doubt on the integrity of police leadership.
"The same time these 13 officers were popping popcorn, taking a nap, relaxing inside this office, I was standing shoulder to shoulder on State Street as we got pounded by rocks from rioters," said First Deputy Supt. Anthony Riccio.
"What makes you comfortable enough that supervisors won't hold you accountable? That means sergeants, lieutenants, commanders, chiefs, deputy chiefs need to step up or step out," Brown said. "I'm not playing."
Brown and Lightfoot said they are in the process of identifying all 13 CPD officers and supervisors involved. Their identities have not yet been released.
Lightfoot also said that she is pushing for the state to pass a law requiring police officers to be licensed and certified by the state.
WATCH: Full press conference with Mayor Lightfoot, Supt. Brown, Rep. Rush
WATCH: Questions and answer session with Mayor Lightfoot, Supt. Brown, Rep. Rush