## The verdict

In summary, these are our reasonable beliefs that a person would have behaved that way producing that sequence of actions (), depending on whether he was a killer () or not ( ), maintaining or not self-control (/ ):
: this is the main point, that makes the hypothesis innocent definitely impossible.
: a cool murderer would have never reacted that way.
: this is the only hypotheses that can explain the action. Here ' stands for not impossible', although not necessarily very probable'34. Let us say that, if Columbo had planned his stratagem, based on a bluff, he knew there were some chances Galesco could reacted that way, but he could not be sure about it.
Given this scenario, the probabilistic inversion' is rather easy, as only one hypothesis remains possible: that of a killer, who even had lost self-control.

Giulio D'Agostini 2010-09-30