Updated

The latest on developments surrounding a federal civil rights investigation of the Chicago Police Department (all times local):

1:30 p.m.

A federal civil rights investigation of the nation's largest police departments has begun in earnest, with Department of Justice agents expected to sit down with top Chicago police brass.

Interim Superintendent John Escalante confirmed during a city council hearing on Tuesday that the meetings would start Wednesday.

These initial meetings are most likely get-acquainted sessions. In coming months, investigators will talk to everyone from beat cops to residents who alleged police misconduct in their neighborhoods.

The DOJ announced the investigation Dec. 7 after the release of video showing a white officer fatally shooting a black teenager.

Chicago police union head Dean Angelo told WTTW-TV he's already met with top DOJ officials. He described it as an off-the-record talk during which he said the union wanted to "help facilitate ... the investigation."