If Illinois legalizes recreational marijuana by ballot measure this November, police may have to "put down" many of the 275 K-9 dogs trained to recognize narcotic substances across the state. Police organizations oppose legalizing marijuana for recreational use, and some marijuana advocates have condemned them for dangling canine death as a political tool. Police agencies invest thousands of dollars and months of training to teach dogs to sniff out and alert officers to the presence of various illegal narcotics, including marijuana, cocaine, heroin, and other drugs. These dogs, affectionately known as K-9 units, are very specialized, and police insist that...