The Highland Park Police chief turned in his badge on Wednesday.
The chief, Lorenzo Veal II, cited difference with the mayor for his resignation.
City taken by surprise
Mayor Deondre Wyndram said the move "came as a complete surprise" and that the resignation takes effect immediately.
"This was real shocking today," Wyndram said. "I didn't expect it. No one expected it here at City Hall. We just saw the chief up here yesterday, so it was a little shocking."
Veal's history as chief
Veal had been on the job for about two years.
"I made a phone call to him and the people from the administration made a call to him today but we haven't been successful at getting in touch with the chief," the mayor said.
About the department
The Highland Park Police Department is comprised of 47 police officers. The deputy chief recently was laid off due to budget cuts. That leaves no one in charge. No word yet on who will replace Veal.
"We know that we have a police force and the police force is still out," Wyndram said. "It may be a minor setback to the chief's position but we still will move forward."