The Deputy Surgeon General of the U.S.Public Health Service was explaining the underlying principles of the theory of crime and guilt.

He narrated the story of a chemist in England who was hauled into court with illegal possession of a still.

The chemist admitted possession of the still, but he could not understand why it was illegal to have one?

He was told that it was because of what he might do with the equipment in his possession.

He then became very much concerned and said he was ready to plead guilty, but he also wanted to plead guilty to other crimes. In particular that of rape.

He was asked whether he actually commited rape?

"No" he said, but I have the equipment for it in my possession".

Reference: 
"Musings of a Physiologist" by Maurice B Visscher,
President of the American Physiological Society, 1948-49.
Amer. J. Physiol. Vol 158, 556-560, 1949.