Former Minneapolis police officer J. Alexander Kueng told a federal jury Wednesday that he'd never encountered such a struggle as when he tried to push George Floyd into a squad car May 25, 2020.

Floyd pushed back, slamming his own face into plexiglass that sectioned off the back of the vehicle, Kueng testified in his federal civil rights abuse trial in St. Paul's federal courthouse.

"His behavior just went to extreme measures," Kueng said, offering his first public recounting of that day's events. "He started shaking very violently."

Floyd seemed to have no pain response, he said, and he wondered if Floyd suffered from excited delirium, like they'd been trained on in the academy.

"I felt I had no control," Kueng said. "I felt like any moment he could shove me off."

Kueng, 28, is on trial, along with fellow ex-officers Thomas Lane and Tou Thao on charges of depriving Floyd of his civil rights during the fatal encounter. He is the second officer to testify in his own defense. Thao took the stand Tuesday and Wednesday.

Kueng answered each question concisely. He said the call to Cup Foods seemed routine — a suspected forgery and a man who may have been standing on top of a car. But when he and his partner, Lane, arrived at the south Minneapolis market, the situation quickly escalated.

Kueng said it worried him when Floyd wouldn't show his hands. He said Floyd then began acting "erratically," dropping to the ground in the middle of the street without caution as a car approached them.

His attorney, Thomas Plunkett, asked if he heard Floyd say he was claustrophobic.

"Yes, sir," Kueng replied. But he said he didn't believe it made sense because Floyd had just been sitting in a vehicle smaller than the squad car. Kueng said he suspected Floyd was on drugs.

At the time, Kueng was new to the force, and though policy dictated that the first squad on scene had control, he said, everyone knew "it's always the senior officer" in practice. In this case, Kueng said, that meant Derek Chauvin, his recent training officer.

He described Chauvin as very quiet, by the book, knowledgeable and commanding respect from other officers, who would defer to him on what to do at a scene.

"Fair but tough," said Kueng, in summing up Chauvin's personality.

Chauvin was convicted of murder by a jury last year in state court and sentenced to more than 22 years in prison. Chauvin, who did not take the stand in his own defense, later pleaded guilty to federal civil rights violations.

Under direct questioning, Kueng talked about growing up in north Minneapolis, the oldest of five children, son of a Black father and white mother. He went to Sheridan Elementary School and graduated from Patrick Henry High School before enrolling in college in New Rochelle, N.Y., to play soccer.

But he tore his ACL and returned home to Minnesota, eventually completing a four-year degree at the University of Minnesota in sociology and criminology. He worked in security and loss prevention at Macy's on Nicollet Mall and became a community service officer with the Minneapolis Police Department shortly before the 2018 Super Bowl at U.S. Bank Stadium.

Like most people in his home neighborhood, Kueng said, "I was not a fan of police whatsoever" while growing up. Without going into detail, he said police once "berated my mother" and that "rubbed me the wrong way." Kueng said he decided to become an officer to do a better job for his community.

Plunkett repeatedly drew attention to the military-style training of police in Minneapolis, starting with Kueng's education for becoming a community service officer.

"Sounds to me you were trained to walk and talk like a soldier," the lawyer said.

"Very much so," Kueng said.

Chauvin served as Kueng's training officer for longer than was normal, he said, and he deferred to Chauvin once he arrived outside Cup Foods.

Kueng, who is seen holding Floyd by the legs in video from that night, said he intentionally restrained him below the waist to stop his legs from flailing. From his training, he said, he knew "the hips are very important for generating power, and ultimately I wanted to avoid the spine."

He said he checked Floyd's pulse and found none, so he informed Chauvin, whom he expected to take action. When paramedics arrived, he said, they didn't seem to be in a rush. That made him second-guess whether he'd overestimated the level of medical emergency, Kueng said.

Before he took the stand, his mother, Joni Kueng, testified briefly that he had played the peacekeeper among the family siblings.

Earlier, co-defendant Thao, 36, testified under cross examination for a second day, saying again how he was focused on crowd control and never touched Floyd.

Assistant U.S. Attorney LeeAnn Bell asked Thao if he had communicated to his partners that Floyd had "stopped speaking, went unconscious and that you had gotten requests from the crowd to check his pulse?"

Thao responded, "How would I know all those things?"

Bell said, "I'm asking if you communicated about any of that."

Thao responded, "No."

He said it was important to restrain Floyd until paramedics arrived because he believed the man had taken drugs, was experiencing excited delirium and might revive and become violent.

Multiple times, he referred to a "19-year veteran" knowing how to care for Floyd. That was a reference to Chauvin, his partner that day.

Bell asked if Thao was in a position to talk to the officers about the restraint on Floyd, who had stopped speaking seconds before Thao told a bystander that someone who was talking could breathe.

Bell said, "You could have called out to your partners from where you were standing."

Thao responded, "It's a possibility."

Lane is expected to testify before the conclusion of the trial, now in its fourth week.

Floyd died after Chauvin had knelt on his neck for more than nine minutes while Kueng and Lane had helped pin him stomach-down in the street, his hands handcuffed behind his back.

Before court started Wednesday, U.S. District Judge Paul Magnuson announced that an alternate juror had been excused because he was ill but not from COVID-19. That leaves four remaining alternates.