In the 2800 block of W. Polk at approximately 6:38 p.m., a 43-year-old male victim was on the sidewalk when an unknown dark-colored vehicle pulled up and an unknown offender exited the vehicle. The offender then produced a firearm and fired shots at the victim. The victim sustained a gunshot wound to the back and was transported to Mount Sinai Hospital in critical condition. Area Four Detectives are investigating.