This series of posts is based on Richard Re’s forthcoming Harvard Law Review article,The Due Process Exclusionary Rule.”

In my first two posts, I argued that the exclusionary rule is in a state of flux and that there are problems with the way that courts are currently approaching this situation. In this post, I’m going to outline an alternative way of understanding the exclusionary rule — namely, as an implication of the constitutional right to due process.

Now, I’m sure that many readers are justifiably skittish about arguments that involve “due process,” in part because that compact phrase has long been used as a basis for all manner of constitutional argument with little connection to constitutional text or history. But my use of due process is actually tightly connected to the core, original meaning of the Due Process Clauses. That original meaning is this: The government must adhere to separately codified procedures for depriving individuals of life, liberty or property.

While scholars widely agree that due process originally required adherence to positive law, they have tended to express this point while discussing (or criticizing) more adventuresome understandings. But accepting the core, original meaning of “due process” as adherence to positive law does not preclude the possibility that “due process” could entail other legal rules. For example, it is possible that due process also gives rise to “substantive” due process, as well as to the evaluation of positive-law processes currently undertaken under Matthew v. Eldridge. Here, however, my argument is simply that due process as positive law establishes the floor, even if not the ceiling, of due process.

Under a positive-law approach, the Fourth Amendment is clearly part of “due process,” but is it part of the “process” specifically for obtaining criminal convictions? At the Founding, the answer was no. In most cases, private parties conducted pretrial investigations, and the unusual searches that were conducted by officials (like customs officials) tended to yield in rem forfeiture proceedings, not criminal actions. In that context, the Fourth Amendment was expected to function as part of the tort process by ensuring that officials who engaged in unreasonable searches would be held liable at tort, just like private trespassers. Consistent with that view, the Founders generally did not suppress illegally obtained evidence.

Today, however, there is a very strong case for viewing the Fourth Amendment as part of the “process” for obtaining criminal convictions. As professional police forces became the nationwide norm during the nineteenth century, it became increasingly common for pretrial investigation to be conducted by government officials. That in turn created increased opportunity for judicial elaboration of Fourth Amendment rules, yielding the beginnings of what we now regard as a constitutional code of criminal procedure. The Fourth Amendment had taken on a new role. Although previously part of the tort process alone, it became a recognized part of “criminal procedure.” Exclusion arose in the wake of that transformation.

Given all this, a criminal conviction violates due process when it is based on illegally obtained evidence. Such a conviction deprives the defendant of life, liberty or property without adherence to separately codified constitutional process. This approach offers a more persuasive basis for the exclusionary rule — as argued in the next post.

The views set forth in these posts are the personal views of the author and do not necessarily reflect those of the law firm with which he is associated.