"These are very serious times and I’m begging you to please stay at home, and parents, please keep your kids at home — doing so is vital to our health," Alton Mayor Brant Walker said at a briefing on Friday.
Walker said he had directed the city's police department to more strictly enforce the order by issuing citations or arresting those in violation of the order.
"We will do whatever it takes to decrease the spread of this deadly virus," Walker said.
The following night, the Alton Police Department cracked down on a social gathering at a local tavern.
Among those they rounded up was the mayor's wife, Shannon Walker.
The mayor apologized to Alton residents on Monday, saying he was "embarrassed" by the incident and that his wife had shown a "stunning lack of judgement."
In a statement, Walker said that the Alton police chief informed him on Sunday at 1 a.m. that officers had stopped a social gathering in downtown Alton that was occurring in violation of the statewide stay-at-home order.
He said that police told him that his wife had also been attending this "prohibited social gathering."
"I instructed the Police Chief to treat her as he would any citizen violating the 'Stay At Home' order and to ensure that she received no special treatment," Walker said in his statement.
He said his wife will face the same consequences "for her ill-advised decision" as the other attendees who violated the order.
"My wife is an adult capable of making her own decisions, and in this instance she exhibited a stunning lack of judgement," Walker said. "I am embarrassed by this incident and apologize to the citizens of Alton for any embarrassment this incident may cause our City."
The Alton police said in a press release that they found several individuals in Hiram's Tavern on Sunday, "clearly disregarding the executive order and public pleas for compliance" on Sunday.
Officers issued a criminal complaint for reckless conduct "against every person found gathering at the bar," police said. Each individual will be summoned to court at a later date. The Class A misdemeanor charge is punishable by up to 364 days in jail and/or a fine of $2,500.
The mayor did not immediately respond to a request for comment.