Let us imagine an example. You are, say, a peaceable citizen on your way home from your place of employment. A police sergeant, detecting you in the crowd, approaches you, lays his hand on your collar, and informs you that you are under arrest for killing a trolley conductor in Altoona, Pa., in 1917. Amazed by the accusation, you decide hastily that the officer has lost his wits, and take to your heels. He pursues you. You continue to run. He draws his revolver and fires at you. He misses you. He fires again and fetches you in the leg. You fall and he is upon you. You prepare to resist his apparently maniacal assault. He beats you into insensibility with his espantoon, and drags you to the patrol box. Arrived at the watch house you are locked in a room with five detectives, and for six hours they question you with subtle art. You grow angry—perhaps robbed of your customary politeness by the throbbing in your head and leg—and answer tartly. They knock you down. Having failed to wring a confession from you, they lock you in a cell, and leave you there all night. The next day you are taken to police headquarters, your photograph is made for the Rogues’ Gallery, and a print is duly deposited in the section labeled “Murderers.” You are then carted to jail and locked up again. There you remain until the trolley conductor’s wife comes down from Altoona to identify you. She astonishes the police by saying that you are not the man. The actual murderer, it appears, was an Italian. After holding you a day or two longer, to search your house for stills, audit your income tax returns, and investigate the pre-marital chastity of your wife, they let you go.