Pencil Drawing~Police Dog

This drawing is said to be of "Chicago's first police dog". The antique dealer who passed this on had several other authentic Chicago Police items that were sold before this item was unpacked. I could not find any information on the first police dog, but the writing on the back of the frame indicates this dog was on patrol in the mid-twenties. It also lists the name of the dog that followed him, and his human partner. The picture is signed, but hard to make out. There is an address listed but the officer's name is blurry from water damage to the back (there is a small amount of water damage to the front of the picture, but it is not on the actual subject). Any history would be greatly appreciated by the owner! Thanks!