Terry Clarke, a 61-year-old Canadian businessman, was with his family in 2015 eating at the restaurant when he got into a physical altercation with Kalhed Shaar.
Several videos from every angle inside the restaurant, as well as patron cellphone video, conflicts with what Shaar told police about the incident.
Clarke, who has a scar from the altercation, accuses Shaar of using excessive force and others for covering it up. He says his life has changed forever.
"He needs to be prosecuted, he is unfit to be a police officer and he is menace to other police officers who have to cover up for him," Clarke said Wednesday.
After the incident, Clarke spent 48 hours in the Cook County Jail. Eventually, he was found not guilty on felony battery charges against a police officer. Meanwhile, Shaar has been relieved of his police powers pending the outcome of an investigation by the Independent Police Review Authority.
Clarke, his wife and their son stopped in Portillos for a burger following a June 2015 Stanley Cup Blackhawks game. During closing time, while several other patrons were still in the restaurant, Clarke says Shaar singled them out and demanded that they leave.
"His attitude towards us was overly aggressive, which seemed strange to me because we were just like everybody else sticking around finishing a burger," Clarke said.
Clarke said Shaar then grabbed his food out of his hand. After, words were exchanged. Clarke said Sharr took his handcuffs and used them as brass knuckles and punched Clark several times.
Clarke's wife Gail said she tried to intervene.
"The blood started to pour out of Terry's face and I just thought, 'I have to get up there.' It was like, 'Stop, just stop hitting him,'" Gail Clarke said.
The Clarkes didn't know Shaar was a police officer because he was wearing shorts, a T-shirt and gym shoes. Terry Clarke said not until he was in handcuffs, arrested for felony battery, did Shaar indicate that he was a cop.
Shaar told police that Clarke threw a chair at him and punched him, which is never seen on the videotape.
"I have no doubt that if there was not video and clear video of what happened and the video wasn't available through a couple different means, I have no doubt that this would have gone considerably different," Terry Clarke said.