Chicago Mayor Lori Lightfoot on Monday fired Police Superintendent Eddie Johnson for lying to her a month ahead of his scheduled retirement.

Lightfoot told reporters Johnson had acted unethically and misled the public after he was found asleep in his police-issued SUV following a night of drinking.

“Eddie Johnson intentionally lied to me,” an angry Lightfoot said.

The firing came in the wake of an inspector general’s report on an October incident in which Johnson was found slumped over the wheel of his vehicle shortly after midnight a short distance from his home. At the time, he said he had had a bad reaction to some medication but later admitted he had gone out to dinner with friends and had a few drinks.

“While I recognize this news comes as a surprise to most of you, this was a decision I felt was absolutely necessary to preserve the legitimacy and honor of the Chicago Police Department,” Lightfoot said in a message to police officers. At the same time, she emphasized: “The old Chicago way must give way to the new reality [of ethical leadership and accountability]. There must be no mistake about the message I am sending today.”

Lightfoot said she had reviewed the IG’s report and examined police tapes of the incident.

“It has become clear that Mr. Johnson engaged in a series of ethical lapses that are intolerable. Mr. Johnson was intentionally dishonest with me and communicated a narrative replete with false statements regarding material aspects of the incident that happened in the early morning hours of Oct. 17. Had I known all the facts at the time, I would have relieved him of his duties as superintendent then and there,” Lightfoot said.

Responding officers did not test Johnson’s alcohol-blood level. He maintained he was tired and had forgotten to take his medication.

“How can I explain it? It’s just your body kind of gives you a warning with the high blood pressure thing that you may pass out, so I pulled over, stopped and I just rested myself until that feeling passed," Johnson said at the time.

Lightfoot already had announced former Los Angeles Police Chief Charlie Beck as interim superintendent Nov. 7 after Johnson announced his retirement. Beck retired from the Los Angeles job in June 2018 after nine years as chief and more than four decades with the LAPD.

Johnson, who grew up in public housing in Chicago, spent more than 30 years with the department. He was appointed to lead the Chicago Police Department in 2016 by former Mayor Rahm Emanuel after the city was roiled by the shooting of an unarmed black teenager by police.