Nov. 29 (UPI) -- Chicago police said an investigation has been opened into a video that shows an officer slamming a man onto the street during an arrest, causing the man to be hospitalized.
The Chicago Police Department said the 29-year-old man had been observed drinking alcohol Thursday afternoon at a covered bus stop on East 79th Street, and officers in an unmarked car detained him.
"The offender then became irate and licked the face of an officer and verbally threatened the officer," police said in a statement to CNN. "Shortly after, the offender then spit in the same officer's eye and mouth. The officer then performed an emergency take down, taking the offender to the ground."
A 43-second video captured by witness Jovonna Alexiss Jamison, who was a passenger in a nearby car, starts moments before the officer lifted the man and slammed him onto the ground.
The footage shows the man motionless on his back for the remainder of the video.
Jamison said she did not see any of the aggressive behavior reported by the police department.
The man "didn't do anything aggressive, he just stood there," Jamison told WFLD-TV. "He was standing there using his cellphone. They took away his bottle of liquor and threw it."
The man was hospitalized for unspecified injuries and was released into police custody at some point overnight, a police spokesman said. He said investigators were speaking to prosecutors Friday about potential charges of aggravated battery of a police officer and drinking in the public way against the 29-year-old man.
Chicago Mayor Lori Lightfoot addressed the footage Friday morning on Twitter.
"While a single video does not depict the entirety of the interactions between the police and the individual, this particular video is very disturbing," Lightfoot wrote.
"It is my expectation that the investigation will be comprehensive and expedited so that the public may gain a complete picture of what happened," she tweeted.
Police spokesman Anthony Guglielmi said the use of the emergency takedown maneuver will be investigated by the Civilian Office of Police Accountability.
That office tweeted Friday that it is "actively seeking witnesses, canvassing for 3rd party video and obtaining evidence related to this incident."