(St. Paul, MN)  —  A Minneapolis police inspector and longtime academy instructor says officers are required to intervene if a colleague uses unnecessary force or puts someone in danger.  Inspector Katie Blackwell testified to the protocol yesterday during the fourth day of testimony in the federal civil rights trial of three ex-Minneapolis police officers.  The officers are accused ignoring their duty to provide aid when fellow officer Derek Chauvin knelt on George Floyd’s neck for more than nine minutes before he died in May 2020.  Blackwell also testified to the training tactics implemented regarding use of force.  A doctor on the team that treated Floyd in the emergency room also testified.  Blackwell is expected to continue her testimony today.