Not long ago, several veteran homicide detectives in Detroit were publicly upbraided and disciplined by their superiors for using the office Xerox machine as a polygraph device. It seems that the detectives, when confronted with a statement of dubious veracity, would sometimes adjourn to the Xerox room and load three sheets of paper into the feeder.

"Truth," said the first.

"Truth," said the second.

"Lie," said the third.

Then the suspect would be led into the room and told to put his hand against the side of the machine. The detectives would ask the man's name, listen to the answer, then hit the copy button.


And where do you live?

Truth again.

And did you or did you not kill Tater, shooting him down like a dog in the 1200 block of North Durham Street?

Lie. Well, well: You lying motherfucker.

In Baltimore, the homicide detectives read newspaper accounts of the Detroit controversy and wondered why anyone had a problem. Polygraph by copier was an old trick; it had been attempted on more than one occasion in the sixth-floor Xerox room. Gene Constantine, a veteran of Stanton's shift, once gave a mindless wonder the coordination test for drunk drivers ("Follow my finger with your eyes, but don't move your head ... Now stand on one foot"), then loudly declared that the man's performance indicated obvious deception.

"You flunked," Constantine told him. "You're lying."

Convinced, the suspect confessed.

David Simon, "Homicide: A Year on the Killing Streets" (1991)