CHICAGO (CBS) — A powerful alderman has defended the Chicago Police Department and ousted Supt. Garry McCarthy, as controversy over fatal police shootings continues to swirl around City Hall.

Ald. Edward Burke (14th), a former police officer and chairman of the City Council Finance Committee, admitted he’s biased, but said he does not support calls for a Justice Department probe of the Chicago Police Department’s use of force.

“I don’t know that Chicago needs the assistance of the Department of Justice when there’s all these other panels and agencies looking at the department,” Burke said.

Illinois Attorney General Lisa Madigan has requested the Justice Department conduct a civil rights investigation of the Chicago Police Department to determine if its use of force violates the Constitution or federal law. Democratic presidential frontrunner Hillary Clinton and Republican Gov. Bruce Rauner also have supported a Justice Department probe, but Burke insisted “there’s no institutional problem” at CPD.

“Will there be individual officers who make mistakes? Absolutely,” he said.

The alderman said there’s no evidence of a conspiracy to cover up the facts in the fatal shooting of 17-year-old Laquan McDonald. Burke also made it clear Mayor Rahm Emanuel’s dismissal of McCarthy would not have been his call.

“I personally think that Garry McCarthy was the finest most experienced police chief of any big city in the nation,” he said.

Burke also defended Cook County State’s Attorney Anita Alvarez, calling her a fine prosecutor, despite many other politicians and protesters demanding her resignation.