With years of allegations of excessive force, biased policing and unconstitutional practices leveled at the Chicago Police Department, it’s a wonder the Department of Justice hadn’t stepped in like it has in cities big and small from New Orleans and LA to Easton Pennsylvania and Beacon New York. That changed Monday when U.S. Attorney General Loretta Lynch announced the Department of Justice is opening up an investigation into the Chicago Police Department. So what exactly happens during these so-called “pattern-or-practice” investigations? And when they are complete, do departments really change? Here to tackle those questions is Stephen Rushin, assistant professor at the University of Alabama, and an expert on Department of Justice examinations of American police departments. (Flickr/Victoria Pickering)