Long before James 'Cracker' Fitzgerald or Jessica Fletcher ever set out on the trail of clues and culprits, there was the keen wit and signature eyepiece of confirmed bachelor Hercule Poirot. The picture of manners and intellectual precision, Poirot mulled over the evidence, pried information from the most secretive of witnesses and always nabbed the right suspect.
The books and show based on his character showcased the procedural style of problem-solving, while also allowing him to delve into the nature of the characters. He was a watcher of the ways of thinking, as well as actions. For every fingerprint or knocked-over vase in an alcove, there was a person's speech that tipped the scale toward the likelihood of guilt, and only the most astute of viewers could beat the detective to the solution.
Hercule Poirot--be glad he's on your side.