A police trainer has testified that ex-officer Derek Chauvin was not trained to use his knee in a neck restraint as he did during George Floyd’s arrest.
Minneapolis use-of-force expert Lt Johnny Mercil said Mr Chauvin should also have later moved the prone Mr Floyd to a different position.
Mr Chauvin, 45, was filmed kneeling on Mr Floyd for over nine minutes during Mr Floyd’s arrest last May.
Mr Chauvin is on trial for murder and has denied the charges against him.
The footage of Mr Chauvin, who is white, with his knee on African-American Mr Floyd’s neck sparked global protests against racism.
With the trial in its second week, jurors have now heard from more than 20 witnesses, including four police training experts on Tuesday. The trial is expected to last for at least one month.
As police officers are rarely convicted or charged at all for deaths that occur in custody, the verdict in this trial is being seen as an indication of how the US legal system will treat such cases in future.
Prosecutors are seeking to prove that Mr Chauvin’s actions violated his training and have focused their questions on police guidelines and strategies taught to help officers de-escalate situations.
Mr Chauvin’s defence attorneys have argued that Mr Floyd’s efforts to resist arrest necessitated the restraint, and that the “hostile” crowd surrounding Mr Chauvin required “unique situational awareness”.
No witnesses at the scene were arrested, and several of them have testified that they urged officers to check Mr Floyd’s pulse and provide him with medical care.
Speaking at a group prayer session outside the heavily fortified courthouse on Tuesday, Mr Floyd’s brother Philonise Floyd, said “after we get the verdict and we get this conviction, we’ll be able to breathe”.