Krysztof Marek, 66, was charged after police said he shot and killed five people in an apartment building in the Dunning neighborhood on the Northwest Side on Saturday.
Marek was charged with five counts of first-degree murder. During his court appearance the judge said he is presumed innocent under the law but "what I have heard today is evil on steroids."
Officers responded to the shooting at around 5:30 p.m. Saturday near the 6700-block of West Irving Park Road. Police said Marek first walked into a second-floor unit and killed four people as they ate dinner. Then made his way up to the third floor, where he shot another woman, police said.
The woman was taken to a hospital in critical condition. She died Sunday, according to county officials.
The victims have been identified as Tzvetanka Kostadinov and Ivaylo Popov, who lived in the apartment, and their guests Iskra Popova and David Hanik. The fifth victim was identified as Jolanta Topolska, who prosecutors said was shot once in the stomach and then, as she tried to get away from the shooter, a second time in the back of the head.
According to Cook County Assistant State's Attorney James Murphy, after the shootings the retired truck driver put the .40-caliber handgun on a coffee table in his condo and walked outside.
"The defendant exclaimed to responding officers, 'I think you're looking for me. I did it,'" said James Murphy, Cook County State's Attorney's Office.
Leading them to the weapon inside his apartment, prosecutors said officers also found two handwritten notes in Polish.
Police found a note taped to Marek's door, written in Polish, which translated to: "No mercy. Remember, whatever s- they do to you, you control it yourself, not them. Enough. You have to pay for it."
Another note read: "Tomorrow. No mercy without any stupid hesitation. Remember who you are. Remember what this piece of s--- is doing to you. Enough."
Prosecutors did not specify what the grudge Marek apparently held against his neighbors was, but they did say the condo association board had recently been trying to evict him for not paying his mortgage or condo association dues, causing conflict with others in the building.
Speaking to reporters on Saturday, CPD First Deputy Superintendent Anthony Riccio said the shooter had a history of problems with his neighbors.
"He knew everybody in the building and everybody knew him," Riccio said. "They say he had anger management issues. He's had confrontation issues with residents before. We don't know what set him off. All we know is that there has been a history between the occupants and him."
Police spokesman Anthony Guglielmi said the incident stemmed from a dispute with his neighbors.
What "he's being accused of is nothing short of savagery," Guglielmi said in a tweet Monday.
Krysztof Marek, 66, formally charged by Detectives & Prosecutors with 5 counts of Murder in connection with Saturday's devastating shooting on the NW side. Incident stemmed from a dispute between Marek & his neighbors and what he's being accused of is nothing short of savagery. pic.twitter.com/U15Mg036cH— Anthony Guglielmi (@AJGuglielmi) October 14, 2019
Mayor Lori Lightfoot called the mass shooting "devastating and almost unfathomable" on Twitter Saturday.
Today’s mass shooting at a condo building on W. Irving Park is devastating and almost unfathomable, except it is happening way too frequently—not only here, but across our country.— Mayor Lori Lightfoot (@chicagosmayor) October 13, 2019
"We mourn the loss, honor the victims, and continue the hard but necessary work of keeping our neighborhoods safe, and taking guns out of the hands of those who are mentally infirm," Lightfoot said.
The Sun-Times Media Wire contributed to this article.