Protesters upset about the conduct of Chicago police have another target beyond Mayor Rahm Emanuel: a much-criticized, quasi-independent agency that was created to investigate complaints against officers but has rarely ruled against them.

The mayor's critics complain that his pledge to reform the Independent Police Review Authority is too limited because it seeks to improve an existing process rather than scrapping the entire structure and starting over.

In the outrage that erupted over the video showing the fatal shooting of Laquan McDonald, Emanuel sacked his police chief and set up a task force to recommend changes. He also replaced the head of the authority known as IPRA.

A former investigator for the authority says he was fired after refusing to reverse findings that one fatal police shooting wasn't justified.