Where the defendant is charged with fleeing or attempting to elude a police officer, it is an essential element of the offense that the officer be wearing a police uniform at the time, and if the officer is in civilian dress, an essential element of the crime is lacking and the defendant cannot be convicted even if the defendant knew that the pursuer was an officer.The 1st District Appellate Court reversed a decision by Cook County Circuit Judge Kevin M. Sheehan.On July 16, 2013, Chicago police officer Christopher Stark …