MINNEAPOLIS — The murder case against former Officer Derek Chauvin in the death of George Floyd went to the jury Monday in a city on edge against round of unrest like the one that erupted last year over the video of the Black man pinned to the pavement with Chauvin’s knee on his neck.

The jury of six white members and six Black or multiracial ones was sent off to begin deliberating after nearly a full day of closing arguments in which prosecutors argued that Chauvin squeezed the life out Floyd last May in a way that even a child knew was wrong.

The defense contended that the now-fired white officer acted reasonably and that the 46-year-old Black man died of an underlying heart condition and illegal drug use.

“Use your common sense. Believe your eyes. What you saw, you saw,” prosecutor Steve Schleicher said, referring to the excruciating bystander video of Floyd pinned down with Chauvin’s knee on or close to his neck for up to 9 minutes, 29 seconds, as bystanders yelled at the white officer to get off.

Chauvin attorney Eric Nelson coun

tered by arguing that Chauvin did what any “reasonable” police officer would have done after finding himself in a “dynamic” and “fluid” situation involving a large man struggling with three officers.

As Nelson began speaking, the now-fired Chauvin removed his COVID-19 mask in front of the jury for one of the very few times during the trial.

The dueling arguments got underway with some stores boarded up with plywood in Minneapolis, the courthouse ringed with concrete barriers and razor wire, and National Guard members on patrol. Floyd’s death last spring set off protests in the city and across the U.S. that at times turned violent.

The city has also been on edge in recent days over the the police killing of a 20-year-old Black man in a nearby suburb on April 11.

Prosecutor Jerry Blackwell had the final word, offering the state’s rebuttal argument. The prosecutor, who is Black, said that the questions about the use of force and cause of death are “so simple that a child can understand it.”

“In fact, a child did understand it, when the 9-year-old girl said, ‘Get off of him,’ ” Blackwell said, referring to a young witness who objected to what she saw. “That’s how simple it was. ‘Get off of him.’ Common sense.”

Under the law, police are given certain latitude to use force, and their actions are supposed to be judged according to what a “reasonable officer” in the same situation would have done — a point the defense stressed repeatedly.

Nelson noted that officers who first went to the corner store where Floyd allegedly tried to pass a counterfeit $20 bill already were struggling with Floyd when Chauvin arrived as backup. The attorney also noted that the first two officers on the scene were rookies and that police had been told that Floyd might be on drugs.

“A reasonable police officer understands the intensity of the struggle,” Nelson said, saying that Chauvin’s body-worn camera and his police badge were knocked off his chest.

During the prosecution’s argument, Schleicher replayed portions of the bystander video and other footage as he dismissed certain defense theories about Floyd’s death as “nonsense,” saying Chauvin killed Floyd by constricting his breathing.

Schleicher rejected the drug overdose argument, as well as the contention that police were distracted by hostile onlookers, that Floyd had “superhuman” strength from a state of agitation known as excited delirium, and that he suffered possible carbon monoxide poisoning from auto exhaust.

The prosecutor sarcastically referred to the idea that it was heart disease that killed Floyd as an “amazing coincidence.”

“Is that common sense or is that nonsense?” Schleicher asked the jury.

But Nelson said the prosecution brought in experts to testify that Floyd died because of asphyxia, or lack of oxygen, while the person who actually performed the autopsy, the county medical examiner, reached a different finding.

Hennepin County Medical Examiner Dr. Andrew Baker, who ruled Floyd’s death a homicide, said Floyd’s heart gave out because of the way police held him down. He listed Floyd’s drug use and underlying health problems as contributing factors.

Nelson also showed the jury pictures of pills found in Floyd’s SUV and pill remnants discovered in the squad car. Fentanyl and methamphetamine were found in Floyd’s system.

The defense attorney said the failure of the prosecution to acknowledge that medical problems or drugs played a role “defies medical science and it defies common sense and reason.”

But Blackwell said prosecutors only have to prove that Chauvin’s actions were a substantial causal factor in his death, not the sole cause.

He also ridiculed the idea that Floyd, who didn’t have a pulse, would come “back to life” and go on a “rampage.”

“That’s the sort of thing you see in Halloween movies., ladies and gentlemen, not in real life. Not in real life,” Blackwell said.