NBC News: Officer who fatally shot Rayshard Brooks disciplined for use of force with firearm

03:27

Family attorney Justin Miller tells Lawrence O’Donnell that the disciplinary history showing the officer who killed Rayshard Brooks had multiple prior complaints, including a reprimand for use of force with a firearm in 2016, was “very troubling” and could be a “very big piece to the puzzle” in building a case against the officer if criminal charges are filed.