Chicago Police Superintendent Eddie Johnson announced his retirement Thursday, just three weeks after he was found asleep behind the wheel of his car.

Johnson — head of the nation's second-largest municipal police force with about 13,500 officers —said he's proud of his work, but that he's ready to take a step back.

"It’s time for someone else to pin these four stars to their shoulders," an emotional Johnson, flanked by his family and Mayor Lori Lightfoot, told reporters. "These stars can sometimes feel like carrying the weight of the world."

He'll serve through the end of the year.

Johnson, 59, was discovered slumped behind the wheel of his SUV in the early morning hours of Oct. 17 after a motorist called 911, Chicago police said. A breathalyzer test was not administered at the scene, but Mayor Lightfoot told the Chicago Sun-Times that Johnson had said to her that he had "a couple of drinks with dinner" before the incident.

While Johnson and Lightfoot declined to discuss that incident — which is being independently reviewed — the superintendent said leading his hometown police force has been a challenge.

"This job has taken its toll — taken a toll on my health, my family, my friends," Johnson said. "But my integrity has remained intact."

Johnson recalled attending a memorial to slain Chicago police officer with Mayor Lightfoot in September.

“The mayor and I were sitting next to the waterfall, when I sat down in that seat, I leaned over her and whispered over to her ear, 'We got to start talking about an end date for me,' "

The superintendent said he made the final decision to retire in early October after a brief family vacation to London when they traveled abroad to see the Chicago Bears.

“It made me feel normal, and I saw them and how they missed me in that kind of setting and that’s pretty much what did it,” he said.

For the past 3½ years, Johnson's police force has been fighting — and making some small dents into — Chicago's infamous murder rate.

The city ended 2018 with 565 homicides, down from 660 homicides in 2017 and 777 in 2016, according to Chicago police data.

Still, those numbers are shocking in comparison to other large U.S. cities. For example, there were 295 homicides in New York,America's biggest city, in 2018 while259 people were slain in Los Angeles last year.

Lightfoot praised Johnson, who grew up in the Washington Heights neighborhood of Chicago, after spending some of his childhood at the Cabrini–Green public housing project.

"Chicago is better because Superintendent Eddie Johnson calls our great city home and because he dedicated his life to serving," she said Thursday.

Earlier this year, Chicago's top policeman also had to deal with the case of "Empire" actor Jussie Smollett, who claimed he was beaten up by two masked men who hurled racist and homophobic slurs at him.

Chicago police could not find evidence of the attack and then accused Smollett of pulling an elaborate hoax. Johsnon did not hold back his emotions in ripping the actor.

Smollett had been originally indicted on 16 felony counts for allegedly filing a false police report before all charges were dropped.

"I’m offended by what's happened and I’m also angry," Johnson said of Smollett on Feb. 21. "I love the city of Chicago and the Chicago police department, warts and all, but this publicity stunt was a scar that Chicago didn’t earn and certainly didn’t deserve. To make things worse, the accusations within this phony attack received national attention for weeks. Celebrities, news commentators and even presidential candidates weighed in on something that was choreographed by an actor."

Johnson was appointed to his job by then-Mayor Rahm Emanuel when the city was still reeling from the 2014 slaying of black teenager Laquan McDonald by officer Jason Van Dyke, who is white and was later convicted of second-degree murder.

CORRECTION (Dec. 3, 2019, 9:35 a.m. ET): A previous version of this article misstated Johnson's age. He is 59, not 60.