A three-pint problem

Certainly going back to Sherlock Holmes we have a tradition of forensic science featured in detective stories.

You look at me as if I were a conjuror,' Holmes remarked, with a laugh.

No man burdens his mind with small matters unless he has some very good reason for doing so.

To a great mind, nothing is little,' remarked Holmes, sententiously.

Crime is common. Logic is rare. Therefore it is upon the logic rather than upon the crime that you should dwell.