In 1930 Dashiell Hammett reviewed mystery fiction for the New York Evening Post. Dismayed at the blunders he encountered, he published 24 “suggestions that might be of value to somebody.” Excerpts:

• The Colt’s .45 automatic pistol has no chambers. The cartridges are put in a magazine.
• When a bullet from a Colt’s .45, or any firearm of approximately the same size and power, hits you, even if not in a fatal spot, it usually knocks you over. It is quite upsetting at any reasonable range.
• When you are knocked unconscious you do not feel the blow that does it.
• Fingerprints of any value to the police are seldom found on anybody’s skin.
• Not nearly so much can be seen by moonlight as you imagine. This is especially true of colors.
• Ventriloquists do not actually “throw” their voices and such doubtful illusions as they manage depend on their gestures. Nothing at all could be done by a ventriloquist standing behind his audience.
• Even detectives who drop their final g’s should not be made to sayin “anythin'” — an oddity that calls for vocal acrobatics.
• “Youse” is the plural of “you.”
• A lawyer cannot impeach his own witness.

Also: “A trained detective shadowing a subject does not ordinarily leap from doorway to doorway and does not hide behind trees and poles. He knows no harm is done if the subject sees him now and then.”