HARLOW: Breaking news just into CNN, the Justice Department is getting ready to announce an investigation into the Chicago Police Department, after a video showing an officer-involved shooting sparked protests throughout the city. Let's take a look at the video that we're talking about here. A source familiar with the situation tells CNN the department will announce a pattern and practice investigation. And that will ask the already ongoing civil rights investigation, the department under intense scrutiny since releasing this video showing the officer shooting 17-year-old Laquan McDonald 16 times, killing him. That officer now charged with first degree murder. The city superintendent, police superintendent has been fired. Joining me now on the phone, CNN legal analyst Sunny Hostin. Sunny, talk to me about, what is a pattern and practice investigation? How common is it? How rare is it?</s>SUNNY HOSTIN, CNN LEGAL ANALYST (via telephone): Certainly, it is not common, but it is something that has happened in other police departments across our country. The investigation is run by the civil rights division. And the goal is really to reform any practices and patterns of, let's say, excessive force or biased policing or any sort of unconstitutional practices. And so in Chicago, this is a department that does have a history of police shootings. It does have a history of many, many complaints from the citizens of Chicago. It certainly has a history of officers not being found accountable for police shootings.</s>HARLOW: All right. You heard it there from Sunny Hostin, our legal analyst, a monumental announcement coming, the Justice Department will launch a pattern and practice investigation into the Chicago Police Department. Straight ahead, I just sat down with New York Senator Kirsten Gillibrand. She was her, right around 9/11, as was I, New York. Her perspective as a New York senator, what she needs to hear from the president tonight on terror. That's next.
Justice Dept. to Investigate Chicago Police