Chicago(CNN) After more than 30 years with the Chicago Police, Superintendent Eddie Johnson is retiring.
"It's time for someone else to pin these four stars on their shoulders," Johnson announced Thursday at a news conference, holding back tears. "These stars can sometimes feel like you're carrying the weight of the world. But I'm confident that I leave CPD in a better place than when I became superintendent."
Johnson will continue to serve in the role through the end of the year, Chicago Mayor Lori Lightfoot said.
Johnson told reporters he wanted to spend more time with his family and added he started thinking about stepping down after a memorial service for fallen officers in September.
"Losing those officers was hard," he said.
But neither Johnson nor the mayor would answer questions about an ongoing Inspector General investigation, which was launched after Johnson was found asleep behind the wheel of his car last month.
The police superintendent said he thought he felt ill because of a change in his blood pressure medication. He told Lightfoot that he "had a couple of drinks with dinner."
An internal investigation was opened at Johnson's request.
Johnson was appointed superintendent in 2016 by then-Mayor Rahm Emanuel as the embattled police department faced criticism for the city's violent crime and officer-involved shootings, including the killing of black teenager Laquan McDonald.
A former Chicago officer, Jason Van Dyke, was sentenced in January to nearly 7 years in prison after being found guilty of charges connected to McDonald's death.
Thursday, Johnson said he was proud of his tenure as the department's top cop, pointing to lower rates of violent crime and officer-involved shootings. Reducing gun violence, he said, has been "one of the greatest accomplishments of my career."
Johnson also detailed his efforts to reform the department, including working with the CPD's critics, enacting new use-of-force policies and helping to bring the department under a consent decree -- a 236-page agreement requiring changes to police procedures.
"I expect that this progress will continue for the years to come, and will help us become the model police department that this city richly deserves," he said.
Johnson, a lifelong Chicago resident, told CNN in an interview that serving as the city's police superintendent has "meant the world to me."
Echoing remarks he made in Thursday's news conference, Johnson said he and the mayor had never discussed his departure prior to the memorial in September.
"I said, 'I think we need to start talking about an end date,'" he said. "And she said, 'OK, when you get ready, let me know.' She never pressed me on it."
Recently, Johnson went to London with his family to watch the Chicago Bears play. It was his first "real vacation" since he took on the job.
"And I saw how much they missed interacting with me ... but on the flip side, I started to realize how much I missed them," he said.
Looking back, he said, he feels good about the progress the department made under his tenure, again referencing lower crime rates and reduced officer-involved shootings. At this point in the year in 2011, he said, there were 91 police shootings, but today, in 2019, there have been 16.
He said he is also proud of investing in the officers themselves, with more technology, tools and staff clinicians.
"Now are we where we want to be? No," he said. "But we've made a lot of progress."
"What I want the people of Chicago to know is this," he said. "You may not always have agreed with the decisions that I made, but I was always doing it, trying to do the right thing. My heart is always in the right place."
"I want nothing, nothing more than every area of this city to be proud of their police department," he said.