A Minneapolis Police Department use-of-force trainer testified in the trial of Derek Chauvin Tuesday and said the former officer was not following his training when he kept his knee on the neck of George Floyd for more than nine minutes.
Kneeling on people's necks is not what officers are taught, Derek Chauvin's former boss told the jury. He has pleaded not guilty. The Hennepin County medical examiner ruled the death a homicide.
Minneapolis use-of-force expert Lt Johnny Mercil said Mr Chauvin should also have later moved the prone Mr Floyd to a different position.
Langenfeld, who tried to revive Floyd before pronouncing him dead, said he surmised that Floyd, a 46-year-old Black man, most likely died of suffocation.
It was testified that police are taught how to interact with suspects who are going through crisis.
The police chief told the court Mr Chauvin's extended use of restraint was "in no way, shape or form" part of department policy or training, "and it is certainly not part of our ethics or our values".
"We may show the younger officers in the academy what that looks like but we don't train leg neck restraints with the officers in-service", he said. "As far as my knowledge, we never have".
Stiger said that after reviewing video of the arrest, "my opinion was that the force was excessive".
The use of force, as it is known, lies at the heart of the prosecutors' strategy.
The first week of the trial was dominated by emotional testimony from eyewitnesses who watched as Chauvin pinned Floyd to the street with his knee on Floyd's neck even as Floyd repeatedly gasped that he could not breathe.
Defence attorney Eric Nelson left and Chauvin are seen in Hennepin County District Court on Tuesday
He said that in his experience, a neck restraint can cause a suspect to lose consciousness in less than 10 seconds.
"Does this appear to be a neck restraint?"
Mr Nelson has suggested that onlookers, many of whom were shouting at Chauvin, might have affected officers' response.
Sgt. Ker Yang, the Minneapolis police official in charge of crisis-intervention training, said officers are taught to "slow things down and re-evaluate and reassess". She said yes, but then was asked by prosecutors whether an unruly crowd excused an officer's duty to render aid. "Only if they were physically getting themselves involved", she said. Even so, the judge said Hall should be able to testify on Floyd's condition in the auto and whether he fell asleep suddenly after possibly taking opioid pills.
The friend, Morries Hall, was in the vehicle with Floyd when police arrived, setting the stage for the attempt to arrest Floyd.
Floyd's girlfriend, Courteney Ross, testified last week that she and Floyd struggled with opioid addiction, and that she thought Hall sometimes illegally sold pills to Floyd.
Mr. Nelson has said if he had the opportunity to question Mr. Hall, he would want to know if he had been the one to give drugs to Mr. Floyd. Chauvin's lawyers argue that Floyd's death was really a drug overdose.
The judge said he was considering allowing Mr. Nelson to only ask Mr. Hall about whether Mr. Floyd had fallen asleep in the vehicle, a possible reaction to drug use. The judge said he would allow Mr. Nelson to draft questions on that topic for the sake of further discussion on Thursday. Prosecutors from the Minnesota Attorney General's office said medical evidence would contradict that.
"Opposing counsel has suggested nearly an alternative perpetrator", Mr. Schleicher said.
Mr Chauvin is on trial for murder and has denied the charges against him.