by Todd Feurer, CBS Chicago web producer

CHICAGO (CBS) — The head of the Chicago Law Department has received a property tax break reserved for a homeowner’s primary residence on both his house in west suburban Naperville and his condo in the South Loop for at least four years.

The mayor’s office insisted the dual tax breaks were an honest mistake, and said Corporation Counsel Mark Flessner will pay back the money he owes.

Flessner moved from Naperville to Chicago in April, a month before Mayor Lori Lightfoot officially appointed him as Corporation Counsel, the city’s top attorney, when she took office.

Before moving to the city, Flessner was claiming a homestead exemption for both homes, even though state law allows homeowners to claim it only at their primary residence.

DuPage County property tax records show a “residential exemption” for Flessner’s home in Naperville from tax years 2015 through 2018. During the same years, Cook County records show homeowner exemptions at Flessner’s Chicago condo.

Lightfoot was asked about the dual exemptions Monday morning, which came to light after she fired Law Department spokesman Bill McCaffrey over the weekend.

“He didn’t have homestead exemptions in two places,” Lightfoot said. “I don’t believe that that’s correct.”

The mayor’s press secretary, Anel Ruiz, backtracked later Monday, acknowledging Flessner received the exemptions for both properties before he was hired by the city.

“Prior to 2019, Mr. Flessner had mistakenly claimed a homestead exemption for both his Chicago and Naperville properties. Now that this mistake has been brought to his attention, he will be paying back the State the amount he received from the additional exemption, which he estimates to be approximately $2,500,” Ruiz stated in an email.

Ruiz said Flessner has not filed a homestead exemption at either home for tax year 2019, the bills for which will be due next year.

Flessner’s residency came under question this weekend after McCaffrey was fired.

Sources told CBS 2’s Brad Edwards that McCaffrey was fired because he raised ethical concerns about the Lightfoot administration, but it’s unclear if those concerns included the dual tax breaks.

Lightfoot vehemently denied that she fired someone for raising ethical questions about her.

“No, definitively not,” she said. “Serious issues regarding professionalism and judgment were raised, and as on the basis of that, there was plenty of information to fire him for cause, which is what happened, period.”

The mayor did not elaborate on those “serious issues,” but hinted McCaffrey had somehow lied about something.

“I think I’ve set a pretty clear standard that in anyone who’s going to work in our administration, they have to do their job at a high degree of competence, they have to be a good colleague, and number three they have to have the highest ethical standards; meaning they can’t lie either through omission or commission. I think I’ve set a very clear standard there,” she said.

Lightfoot also admonished reporters for tweets about purported reasons for the firing over the weekend, in which they cited unnamed sources.

“I have to say I’m disappointed that, on the basis of a single source, unnamed, that you all are putting this out,” she said.

Several reporters tweeted praise for McCaffrey over the weekend after he was fired.

“Obviously Bill McCaffrey was your buddy, but I hope that we are not getting to a new standard in media here in Chicago where we have a bunch of unnamed sources that there’s no other information provided,” Lightfoot said. “They’re just throwing out a bunch of chum on the water, and people are biting at it as if it’s the truth, because the things that have been put out that I’ve seen are demonstrably false, and could easily be proven so with a little bit of diligence, which is what I would assume reporters who are serious about this would do.”

McCaffrey had worked at City Hall for 15 years as a spokesman for various agencies, most recently at the Law Department.