A police commander was fatally shot while responding to a call Tuesday in downtown Chicago, authorities said.

Cmdr. Paul Bauer, 53, went after a suspect who had an altercation with other officers and escaped, police Superintendent Eddie Johnson said. The commander had been attending training and heard an alert, CNN affiliate WBBM reported, CNN reports. 

Bauer, a 31-year veteran, encountered the individual and was shot several times, Johnson said.

At first, Johnson had said Bauer was off-duty when he responded to a radio call by tactical officers patrolling a nearby area.

But Officer Anthony Guglielmi, a spokesman for Chicago Police, tweeted early Wednesday that he was on duty.

"CPD Commander Paul Bauer was on duty when he was murdered this afternoon," Guglielmi said. "Initial reports from the scene of him being off duty were incorrect and updated."