This Colt Official Police .38 Special is circa 1937. The bottom of the grip strap is marked I.S.P.-M-DEPT. 25 No. 9. Illinois, Indiana, Iowa, Idaho State Police - you take your pick (or get a Colt letter). We believe the M stands for a motorcycle unit which, in our opinion, makes it most likely an Illinois State Police gun. The 4" barrel has an excellent bore with bright, strong rifling. The gun has approx. 92% blue with the gripstraps turning. The checkered grips are very good with the expected issue wear. The action functions properly. This very nice example of a pre-WWII Colt Official Police 38 with state police use is ready for your Colt or police collection.