The criminal justice system, in theory, must be impartial. The only admissible considerations within the system, in theory, are intended to derive from a dispassionate weighing of facts in evidence.
This dispassionate, logical approach—deriving in many ways from Enlightenment philosophy—is frequently taken for granted, at least implicitly. Yet the realm of criminal justice is fraught with anomalies, many of which have their roots in human psychology rather than in the abstractions of legal theory.
Major cases attest to this fact. The Scott Peterson criminal trial of 2004, in which Peterson’s pregnant wife was murdered, resulted in Peterson’s conviction for the crime despite there being no direct physical evidentiary connection from the crime to Peterson. The Wesson multiple murder of Marcus Wesson’s own children in Central California, also in 2004, did provide direct evidentiary connections, but some specific connections were incompletely or inaccurately conveyed to the jury.