CHICAGO (CBS) — A judge has issued an arrest warrant for a man wanted in the slaying of a cab driver over Labor Day weekend, but police said the man is now in China.

Anis Tunkegar, 64, died on Sept. 4, two days after he was kicked in the head during a fight with another driver in the West Loop.

The family’s attorney has said surveillance video shows Tunkegar walking over to an Uber driver around 3:45 p.m. on Sept. 2, to complain that the Uber driver had damaged his taxi.

Tunkegar then goes to the passenger side and flips a side mirror.The Uber driver gets out and delivers a roundhouse kick to Tunkegar’s head.

“I don’t know of any legitimate justification for roundhouse kicking an individual for flipping a mirror,” said attorney Michael Gallagher.

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Tunkegar was knocked out, and was taken to Northwestern Memorial Hospital in critical condition. He was pronounced dead two days later.

Tunkegar’s son was in New York when his father was beaten, and he flew to Chicago to see his dad as he fought for his life in the hospital. He said his father’s face was almost unrecognizable due to his injuries.

“My father died a violent death. No one deserves to be beaten to death, and leaving behind children and a wife with all these questions is unspeakable ,” Omar Tunkegar said.

The Uber driver who kicked Anis Tunkegar was arrested after the fight, but was released without charges.

Three months later, police were able to secure an arrest warrant on a murder charge for the Uber driver, Lu Fangqi, but he went to China after he was released in September.

“Police are working with the State Department and Chinese authorities to bring him back to stand trial for the murder of Anis Tunkegar,” Chicago Police Department spokesman Anthony Guglielmi said.

Uber has said Fangqi was removed from the ride-hailing platform on the day of the incident.