Bernard Kersh never made it to Thanksgiving dinner.

His mother, Keshia Johnson, lost touch with her son on Thursday afternoon in the middle of a phone call. It was interrupted by police. They had just approached Kersh at a Chicago bus stop, suspecting him of drinking in public.

But it wasn’t until she saw a viral video that Johnson understood what happened. Chicago Mayor Lori Lightfoot (D) would later call the footage “very disturbing.” It showed an officer bear-hugging Kersh from behind as the 29-year-old stood facing the patrol car, lifting Kersh in the air — nearly over the officer’s head — and then smashing him headfirst onto the curb. A black object, apparently a phone, popped onto the sidewalk. Kersh lay motionless.

Now, amid public outrage over the officer’s actions, Kersh stands charged with aggravated battery for allegedly spitting in the officer’s face — the offense that police say prompted the violent arrest.

On Sunday, Kersh pleaded not guilty to the charges, which include resisting arrest, simple assault and a citation for drinking in public, his attorney said. He appeared in court with support from the Rev. Jesse L. Jackson and a team of civil rights lawyers, who explained to a judge that Kersh has been diagnosed with schizophrenia. Prosecutors and the police union argued that the officer’s actions were warranted, calling the maneuver an “emergency takedown” after Kersh allegedly spit in the officer’s eye, the Chicago Tribune reported.

But Andrew M. Stroth, one of Kersh’s attorneys, described it as an excessively brutal “martial arts” stunt that could have killed his client.

“You have an unarmed person who, from our perspective, presents no threat to the officer, and what Bernard said is that all of a sudden that officer did that takedown move and bashed his head against the cement,” Stroth told The Washington Post. “The video speaks for itself. He could have easily been killed.”

Lightfoot announced Friday that the city’s Civilian Office of Police Accountability would be investigating the incident “so that the public may gain a complete picture of what happened.” In a statement, police spokesman Anthony Guglielmi said the officer had been “relieved of police powers” pending completion of the review.

According to a statement from police, officers encountered Kersh about 4 p.m. on Thursday at a bus stop in the Chatham neighborhood and approached him on suspicion of drinking vodka in public. Cook County prosecutor James Murphy said Sunday that Kersh “became combative as soon as the officers started talking to him.” Officers intended to write a citation for the public drinking, but Kersh started “threatening” them and resisting arrest, police said. He allegedly licked an officer’s face twice, then spit in his eye, a narrative that Stroth disputes.

“There was a substantial amount of spit, in liquid form, that landed in the eye of [the officer]” and dripped down into his mouth, Murphy said, the Tribune reported.

Guglielmi said in a statement to The Post that officers are trained in how to perform “emergency takedowns,” which he defined as “maneuvers that are designed to subdue an individual during a physical threat to a citizen or police officer.”

Asked what the emergency in this case was, Guglielmi said: “While the department stands by the criminal charges against the defendant, Internal Affairs and the independent Office of Police Accountability are scrutinizing the actions prior to that emergency take down very closely. If any wrongdoing or policy violations are discovered, officers will be held accountable.”

Kersh was transported to a hospital for treatment after the body slam, though prosecutors claimed in court Sunday that his injuries were no worse than a scratch on the face “the size of a fingernail,” the Tribune reported. Stroth told The Post that Kersh’s family doubts that claim, fearing he suffered a serious brain injury.

For a while, Johnson didn’t even know whether her son was alive, she told local news outlets on Friday.

Johnson told ABC7 that Kersh left to pick up some alcohol for the family get-together on Thursday afternoon but disappeared. “We were waiting to eat Thanksgiving dinner for him, because he always blesses the table,” she told the news station. Finally, around 7:30 that evening, Kersh’s father called her, asking whether she had seen the video. Johnson took a look.

“To see them just slam him to the concrete like that, you know, that was hard to watch,” she told NBC Chicago. “I can’t say [if he spit] or not, but if he did, I still don’t think he deserves to be slammed on his head. He could have killed my son. He could have broke his neck. He could have not woken up.”

The woman who filmed the viral video, Jovonna Jamison, told ABC7 she was so worried for Kersh that she started praying.

But Martin Preib, spokesman for the Chicago police union, told reporters during a news conference that the officer’s actions were reasonable and that the officer should have never been removed from his duties. He called the charges against Kersh “totally appropriate.”

“It’s right there in the law: You can’t spit on police. You can’t lick 'em either,” he said.

Prosecutors also noted at the Sunday bond hearing that Kersh has a criminal history that includes convictions for assaulting a police officer and resisting arrest while spitting at an officer. But Stroth said he believed Kersh’s encounters with police “have been largely attributed to his mental health issues.”

After the hearing, civil rights activists including Jackson and the Tree of Life Justice League described the incident as a continuation of years of police brutality in black neighborhoods. Jackson, whose organization, the Rainbow PUSH Coalition, paid Kersh’s bond, said he hoped Lightfoot would use the case to take a stand against excessive force by police.

“He needs mental care. But the police had no basis for throwing him down in a way that could have killed him. We’ve seen this before, and it must stop,” Jackson said, CBS Chicago reported. “I hope that the mayor and those involved will move immediately to deal with this police officer and those who stayed silent and did nothing.”

Stroth said Kersh will be undergoing a more complete medical examination this week. At the news conference, Johnson said the pain in her son’s head has not gone away. Whatever her son may or may not have done, she said she believes there were other ways for the police to handle the situation.

“I mean, how about handcuff a person?” Johnson said.