The Fundamental Fairness Doctrine allows states to define their own provisions with respect to the way accused criminals are treated by local and state law enforcement, as long as the accused are still treated fairly. It is based on two cases: Powell v. Alabama in 1932 and Brown v. Mississippi in 1936. The decision of the Brown v. Mississippi case resulted in the ending of physical coercion (torture) in eliciting confessions from the accused.
The Incorporation Doctrine differs from the Fundamental Fairness Doctrine in that the states are not permitted to create their own definitions with respect to procedural regularity (law enforcement and the judicial process) but instead must follow procedures EXACTLY as defined by the United States Supreme Court when it comes to the civil rights of the accused. It is most often referenced with respect to the Warren Court's decisions during 7 landmark cases throughout the 1960s, starting with Mapp v. Ohio in 1961 and ending with Washington v. Texas and Klopfer v. North Carolina, both in 1967. These cases were all about "policing the police," and resulted in the establishment of policies and procedures about the exclusionary rule, self-incrimination, assistance of counsel, confrontation of witnesses, compulsion of witnesses, the right to a speedy trial, and the barring of cruel and unusual punishment.