The “checkered band” on hats worn by Chicago Police Department officers was introduced in May 1967 by Superintendent O.W. Wilson. The design was based on the three-layer “Sillitoe Tartan” first used in 1932 by the Glasgow Police Department in Scotland and named after Chief Constable Percy J. Sillitoe.
Supt. Wilson chose to use a two-layer pattern, with white and dark blue for police officers, and yellow and dark blue for supervisors. Security guards in Chicago were prohibited from using this hat design as a means to immediately distinguish city police officers from private security guards.
Only a few departments in the United States wear a checkered band on their uniform hats, including the Cook County Sheriff’s Police Department as well as a few Chicago suburban agencies and the Pittsburgh Bureau of Police in Pennsylvania, who wear the three-layer version.