MINNEAPOLIS — Derek Chauvin had one knee on George Floyd’s neck and another on his back and was pressing down with most of his body weight for the entirety of the nine minutes and 29 seconds the Black man was restrained, handcuffed and facedown on a street, a use-of-force expert testified Wednesday.

Jody Stiger, a longtime Los Angeles Police Department sergeant and prosecution witness, said Chauvin never moved, according to his review of police body-camera footage, and also appeared to be gripping Floyd’s hand in an effort to inflict pain on the man, even though he was no longer resisting.

During his second day of testimony at the former officer’s murder trial, Stiger told the jury that Chauvin appeared to be using a “pain compliance” technique on Floyd’s hand, “squeezing fingers or bringing knuckles together” and pulling his wrist into his handcuffs — an effort usually deployed by officers trying to gain control of a suspect. But because Floyd stopped resisting the moment officers placed him in a prone position on the ground, “at that point, it was just pain,” Stiger said.

Stiger, a paid expert witness who has been a use-of-force trainer with the LAPD, said he never saw Chauvin ease up in his use of force, even as Floyd appeared to be in “distress” and ultimately stopped moving. He reiterated his view that officers initially responded with “reasonable force” when Floyd resisted as they struggled to place him inside a squad car.

But Stiger said the force should have stopped once Floyd was on the ground and not resisting. When Chauvin continued to pin Floyd to the ground, Stiger said, it turned into “deadly force.”

“At the time of restraint period, Mr. Floyd is not resisting. He was in the prone position,” Stiger told jurors. “He was handcuffed. He was not attempting to evade. He was not attempting to resist.”

The pressure of Chauvin’s body weight — estimated by another witness to be about 140 pounds along with 40 pounds of police equipment, including body armor — would have put Floyd at risk of “positional asphyxia,” a danger that is mentioned in most police training, Stiger said.

Floyd was already at risk for potential breathing problems because he was handcuffed and facedown on the ground, Stiger testified. “When you add body weight to that, it just increases the possibility of death,” he said.

As he has with other witnesses, Chauvin’s defense attorney, Eric Nelson, tried to raise doubt about the positioning of his client’s knee. He showed Stiger still photos taken from video footage of Floyd’s arrest that he said showed Chauvin’s knee on Floyd’s shoulder or back, not his neck. But Stiger steadily disagreed, arguing the photos showed Chauvin’s knee on or at the base of Floyd’s neck.

Defense attorney Eric Nelson argued on April 7 that George Floyd’s “active resistance” could have impacted the defendant's reasonable use of force. (The Washington Post)

Nelson asked Stiger whether there are limits to what camera footage can show — an assertion Stiger agreed with. But when Nelson asserted that body-camera videos might not capture the “feeling” at the scene or the “tension” in someone’s body, Stiger again disagreed. Under prosecution reexamination, he argued that Chauvin’s training should have led to him to realize something was wrong with Floyd.

“As time went on, clearly in the video you could see Mr. Floyd’s health was deteriorating. His breath was getting lower. His tone of voice was getting lower. His movements were starting to cease,” Stiger said. “At that point, as an officer on scene, you have a responsibility to realize that, okay, something is not right. Something has changed drastically from what was occurring earlier.”

Nelson sought to defend the officers’ response to Floyd’s cries for help, pointing out that Floyd had told officers “I can’t breathe” earlier when he was “actively resisting” attempts to put him inside a squad car. He asked Stiger whether he had ever had an instance of someone “faking a physical ailment” during arrest, to which Stiger replied that he had.

Stiger’s testimony came as prosecutors began to shift from police testimony into the larger investigation of Floyd’s death.

Agents with the Minnesota Bureau of Criminal Apprehension, an agency that examines instances of police use of force by and took control of the case from the Minneapolis Police Department, were called to testify about evidence in the case, including initially overlooked pill fragments found earlier this year during a second search of the squad car officers had tried to place Floyd in.

That testimony early on focused on the body-camera footage of Floyd’s arrest. At one point, Nelson played a short clip of footage taken from Officer J. Alexander Kueng’s body camera showing Floyd pleading with officers.

He asked James Reyerson, a senior special agent with the BCA who was in charge of the agency’s investigation of Floyd’s death, what he thought Floyd had said.

“Did it appear that Mr. Floyd said, ‘I ate too many drugs?'" Nelson asked Reyerson.

Reyerson asked for the video to played again. Upon second viewing, the agent replied, “Yes, it did.”

It was a brief victory for Chauvin’s defense, which has argued that Floyd died of a combination of preexisting health issues and a drug overdose, citing an autopsy that recorded high levels of fentanyl and other substances in Floyd’s system.

But after a brief recess, prosecutor Matthew Frank called Reyerson back to the stand and played a longer clip of the video, which he said offered “context.” The footage showed officers talking to Floyd about potential drug use.

Asked what he believed Floyd had said, having viewed the longer clip, Reyerson testified, “I believe Mr. Floyd was saying, ‘I ain’t do no drugs.’”

Nelson did not challenge Reyerson’s statement or question him about the video again.

Prosecutors also asked Reyerson about the instances Nelson has cited to argue that Chauvin’s knee may have been resting on other parts of Floyd’s upper body — showing him video clips associated with those time stamps instead of still photos. Reyerson said Chauvin’s left knee appeared to be on Floyd’s neck, with his right knee on Floyd’s back.

“Does it appear that Mr. Chauvin is using his weight to hold Mr. Floyd down?” Frank asked.

“Yes, it does,” Reyerson replied.

Reyerson testified that he was one of 50 agents assigned to the Floyd case, one of the largest in the agency’s history, and that they often worked with more than two dozen FBI agents assigned to the case. He estimated they interviewed more than 200 people and analyzed extensive video, photographs and other evidence.

Reyerson testified that he interacted with Chauvin when he photographed the officer and the gear he was wearing, including body armor and other equipment, at City Hall, where the officers had been taken for questioning after Floyd’s death.

Reyerson acknowledged the agency initially missed some evidence in the case. In December, prosecutors asked agents to conduct a second search of the car Floyd was driving, based on photographs. Among the items collected were two white pills found in the car’s console that laboratory testing later confirmed to be methamphetamine and fentanyl, and two packets of Suboxone, an opioid addiction medication.

Last week, Floyd’s girlfriend testified about their struggle with opioid addiction.

In January, defense attorneys for Chauvin and the other officers at the scene asked for a second search of Squad 320, the car officers tried to place Floyd in the night of his death. Agents recovered pill fragments that were later found to contain Floyd’s DNA and a combination of fentanyl and methamphetamine.

McKenzie Anderson, a BCA forensic scientist who was in charge of evidence collection at the scene 38th Street and Chicago Avenue, testified that she had seen the white substances on the back seat of the car last summer, when the car was taken into custody. But she said she had focused on testing blood found in the back seat.

“At the time I didn’t give it any forensic significance,” she testified.

Anderson testified that no evidence was taken from the scene outside Cup Foods, where the incident occurred, other than Floyd’s SUV and the police car taken for processing. It rained at the scene, possibly clearing away blood on the ground, said Anderson, who testified that she responded to about 30 crime scenes last year.