89-year-old dementia patient repeatedly punched by medical worker, video shows

(INSIDE EDITION) - The family of an 89-year-old dementia patient has released horrifying video that shows the man being punched repeatedly by a nursing home employee.

"It was gut-wrenching," the man's grandson, Daniel Nassrallah, told InsideEdition.com Wednesday. "Literally, my legs collapsed" after viewing the footage, he said.

Relatives of Georges Karam installed a video camera in his room at the Garry J. Armstrong long-term care center in Ottawa, Canada, after the elderly man suffered numerous, unexplained injuries, they said.

Nassrallah said the facility "never really gave us an answer" about the bruises and cuts they found on Karam's body, so with the center's permission, a baseball-sized camera was installed on the wall facing the man's bed in February, said Nassrallah, an attorney. The staff was told about the device, he said.

A few weeks later, Nassrallah said, he and his wife were watching the footage from his grandfather's room when they saw a caregiver enter, and act aggressively. "He threw him around the bed," Nassrallah said.

"My grandfather started to flail and tried to bat him away," he said. "Then he started punching my grandfather in the head."

The video shows the employee, Jie Xiao, hitting the man 11 times. Nassrallah said his grandfather is non-verbal and confined to a wheelchair.

Nassrallah called police and headed with his brothers to the nursing home, he said. They encountered Xiao in the lobby and escorted him upstairs, where the police had already arrived, he said.

Nasrallah used his cell phone to show officers the video from his grandfather's room.

Xiao was arrested. He pleaded guilty to one count of assault on June 27 and is free on bail pending his sentencing hearing, Nasrallah said.

He has been fired and police are investigating whether other patients were harmed.

"The safety and well-being of all of our residents is our No. 1 priority," Janice Burelle, general manager of Ottawa community and social services, told the Ottawa Citizen.

"We take our commitment to safety seriously," she said.