Zimmerman, who runs the department's homicide division, was one of several supervisors who testified in Chauvin's murder trial Thursday and Friday. Their role was twofold: to describe how the murder investigation evolved, and to serve as experts on the way Chauvin pinned Floyd under his knee for about nine minutes — continuing to press down on his neck even after Floyd lost consciousness — and how it flouted the department's use of force policies.
Zimmerman said that he, like all officers on the force, had to take continuing education training to maintain his license as an officer, and that he'd been taught for more than 30 years that once suspects are restrained in handcuffs, they need to be taken off their stomachs, because lying prone with their hands behind their backs can affect their ability to breathe.
The way Chauvin held Floyd, Zimmerman said, qualified as deadly force under Minneapolis Police Department policy.
"Pulling him down to the ground facedown, and putting your knee on his neck for that amount of time — it's just uncalled for," Zimmerman said. "I see no reason why officers felt they were in danger, if that's what they felt. And they would have to feel that way to use that amount of force."
Zimmerman based his opinion on both police body-worn camera footage and a bystander video taken by Darnella Frazier, who was 17 years old when her cellphone video of Floyd's death went viral on social media. Her footage of a Black man gasping for breath under the knee of a white police officer rekindled a nationwide racial justice movement last summer.
Chauvin is accused of killing Floyd last Memorial Day during his arrest for allegedly using a $20 counterfeit bill at a convenience store. Floyd lay handcuffed and on the ground, pleading and saying he couldn't breathe as Chauvin dug his knee into Floyd's neck. He continued to do so even after Floyd lost consciousness.
On Thursday and Friday, police described how the investigation into Floyd's death began.
Sgt. David Pleoger, the shift supervisor on duty the evening Floyd died, testified Thursday that he was first alerted of the arrest by Jena Scurry, a 911 dispatcher who testified on March 29 that she had watched Floyd's arrest on a live security feed and called Pleoger about it.
In their recorded phone conversation, she said she wasn't sure if she was witnessing a use-of-force situation that would require review, but she told Pleoger she was startled by the way three officers restrained Floyd, saying, "all of them sat on this man."
According to Pleoger's testimony, he then called Chauvin, who reported that Floyd had been "combative." After a struggle, Chauvin told his sergeant, Floyd had "suffered a medical emergency." Chauvin did not tell him then about the way he'd restrained Floyd, Pleoger said.
Body camera footage showed that Pleoger then drove to the scene of Floyd's death and interviewed the three other officers. He told two of them to try to find witnesses, and had Chauvin and his partner meet him at Hennepin County Medical Center, where staff were trying to revive Floyd.
Pleoger first learned the investigation would have to be sent up the chain of command at the hospital. There, Chauvin first revealed that he'd pressed his knee into Floyd's neck while Floyd was in handcuffs. Any use of force while a suspect is restrained goes to Internal Affairs, Pleoger said. When Floyd was pronounced dead, the arrest became a "critical incident," Pleoger testified.
He called Sgt. Jon Edwards, who was taking over for him as supervisor on the night shift, and asked Edwards to secure the intersection where Floyd was arrested.
During testimony Friday, Edwards described taping off the area, having his officers canvass the neighborhood to look for witnesses, and helping investigators arrange a tow for one of the squad cars and for Floyd's car.
When he arrived on the scene, he said, he found Thomas Lane and J. Alexander Kueng, the two other officers who'd held Floyd down as Chauvin pinned his neck. He told them to wait there and "chill out," because he knew they'd have to go downtown for questioning. They needed to be transported separately, he said, as witnesses in, and possibly subjects of, an internal investigation.
Zimmerman also reported to the scene after Floyd was pronounced dead at the hospital.
"I get called for every suspicious death. I go out to the scenes," he said. "Homicide responds initially to critical incidents, and a critical incident can be anything from a death to a serious injury to officers or the public."
He said once agents for the Minnesota Bureau of Criminal Apprehension arrived on the scene, he began assisting them with the investigation.
Both Pleoger and Zimmerman also served as expert witnesses on the use of force.
Officers must use force proportional to the threat they perceive, Zimmerman said. He'd never been trained to kneel on a suspect's neck, he said, adding that would be considered "top tier deadly force," because "if your knee is on a person's neck, that can kill him."
Once a suspect is in handcuffs, he said, that person becomes an officer's ward, and is no longer considered dangerous.
"He's your responsibility. His safety is your responsibility. His well-being is your responsibility.
Once a person is cuffed, the threat level goes down, all the way," he said. "You could have some guy try to kick you or something, but you can move out of the way. ... The threat level is just not there."
Floyd was already in handcuffs before he was taken to the ground, police body camera videos show. He was held in the prone position for about nine minutes.
Zimmerman also testified that once police secure or handcuff a person, they "need to get them out of a prone position as soon as possible."
"Your muscles are pulling back when you're handcuffed and when you're laying on your chest," he said. "That's constricting your breathing even more."
On cross-examination, Chauvin's attorney, Eric Nelson of Halberg Criminal Defense, framed Zimmerman as an armchair quarterback. Nelson noted it's been nearly 30 years since the lieutenant has had to implement his use-of-force training on a regular basis.
"You're not out actively patrolling and arresting people for less serious offenses," he said. "When's the last time you got in a physical fight with a person?"
Zimmerman said it was 2018, and Nelson noted that was a few years ago.
Nelson also pointed out that officers base their decisions to use force on a range of considerations, such as a suspect's prior behavior and level of intoxication, as well as whether the scene is known to be a high-crime area, whether there are bystanders around, and the best way to maintain the safety of an officer's partner and the safety of civilians in the area.
Pleoger served as an expert witness as well during his testimony Thursday, answering questions about "positional asphyxia."
"If you restrain someone, or leave them on their chest or stomach for too long, their breathing can be compromised," Pleoger said, adding that police are trained to roll suspects onto their sides once they're restrained to avoid positional asphyxia.
On cross-examination, Nelson asked the sergeant about the department's critical decision-making model, which requires that officers take in their surroundings, assess a situation and continually modify their response.
Nelson also noted that police sometimes have to decide between administering medical aid and dealing with danger. He offered the sergeant the hypothetical example of an officer being in a gun battle while a victim goes into cardiac arrest. Pleoger agreed he wouldn't be able to administer aid until the shooting stopped.
On redirect, Steve Schleicher, a partner at the Minneapolis law firm Maslon LLP who is working pro bono for the prosecution, addressed both those points. He noted that the sergeant had reviewed the police body camera footage from last May, and he asked if he'd observed a gun battle. He had not.
"If a suspect is no longer breathing," Schleicher said, "would it be necessary for an officer to take that into account and reassess what they're doing?"
"Yes," the sergeant said.
--Editing by Bruce Goldman.
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