Watch Live: Senior Police Officer Says Neck Restraint Of Floyd Was 'Uncalled For'

The officer with the most seniority on the Minneapolis Police Department said on Friday that he's never been trained to put his knee on someone's neck, noting that doing so could kill someone.

The senior officer, Lt. Richard Zimmerman of the homicide unit, also testified that putting someone in handcuffs brings the threat level "way down" – and he said anyone who is cuffed while facedown on the ground should be moved immediately.

The trial has entered a more technical phase, centering on officers' application of police policy and Floyd's medical status in the final minutes of his life.

Zimmerman was called to the scene outside the Cup Foods in south Minneapolis last May,