Okay, I have TOTALLY figured it out! Years and years of wondering, and absolutely no answer, here it is. It dawned on me today:
I had seen an episode of “Cops” once where a person was asked to step out of the car for a sobriety test. The suspect was unable to walk due to paraphenilia in his shoe. Well, there’s the answer. A person gets pulled over, while walking outside of the car for a sobriety test the cop suspects something in his shoe. The shoe is removed, the paraphenilia taken out of the shoe, the suspect arrested, and the shoe left there. It’s simple. Hope that answers that mystery!