Cmdr. Bauer was taken to Northwestern Memorial Hospital where he was pronounced dead. Superintendent Johnson said the police arrested a suspect and found a gun.
Johnson said the suspect is in custody and police have recovered the weapon. Gugliemi said on Twitter the officer was shot by "an assailant". Police said that's when the suspect shot him several times, fatally wounding the commander.
Officers said over the radio that the suspect took off running.
The shooting occurred at the Thompson Centre, a building in downtown Chicago that hosts government offices.More news: Political crisis in South Africa: President Jacob Zuma told to step down
More news: Aly Raisman in SI swimsuit issue
More news: Salon asks ad-blocking visitors to mine cryptocurrency
And on Wednesday, Richardson (Texas) Police Officer David Sherrard, 37, was shot and killed while responding to a disturbance at an apartment complex.
"There's a radio laying (sic) next to him. Maybe I'm jaded, I don't think that's anything to be proud of", he said. The I-Team has learned the officer was shot twice in the head. "So they took him with shackles and then they put him in the squad". I heard that the door is locked there.
"I know there is a perception out there that there is this wall, a lot of mistrust in the Police Department", he said. "This afternoon, a CPD commander was shot while assisting fellow officers", Johnson wrote in an email to members of the department.
"People were shouting at each other, because people thought it was a riot, and so did we", said Gloria Schmidt, who said she had been inside a nearby courthouse and came outside shortly after the shooting.
Commander Bauer is survived by his wife and daughter. "They taped it off, so we couldn't get out".