A Retreat from Exclusion
As you just read, the Court has watered down Fourth Amendment protections on the front end by downgrading the warrant requirement to something more akin to a warrant presumption. At the same time, the Court has watered down Fourth Amendment protections on the back end by sharply tailoring the availability of its chief remedy. Though other remedies exist, the exclusionary rule long has been the primary method for redressing violations of the Fourth Amendment. The Court's current understanding of the exclusionary rule, however, makes it far less available.
When the exclusionary rule was first adopted, the exclusion of unconstitutionally obtained evidence was understood to be required by two distinct, but equally robust, rationales. First, notions of judicial integrity made it inappropriate for courts to rely on evidence that had been obtained through violation of the Constitution. As the Court explained in its now-overruled decision Weeks v. United States, the “tendency of those who execute the criminal laws of the country to obtain conviction by means of unlawful seizures and enforced confessions ... should find no sanction in the judgments of the courts, which are charged at all times with the support of the Constitution.” The second rationale for excluding evidence was that exclusion was thought to deter future police misconduct. The thinking was if the police could not profit (in the sense of admissible evidence) from their bad behavior, officers would be less inclined to break the law in the first instance.
However, the Court has retreated entirely from “judicial integrity” as a rationale for exclusion. Currently, the deterrence of future misconduct is seen as the only justification for excluding evidence. This shift to deterrence only has meant that far less gets excluded. While judicial integrity is a broad rationale that keeps virtually all unconstitutionally obtained evidence from the fact-finder, deterrence is a much narrower rule. In cases where police conduct cannot be characterized as entirely purposefully, it may be difficult to conclude that exclusion will deter future violations. Consequently, Fourth Amendment violations occasioned by police ignorance, inattention, and even sheer incompetence all have been found not to require exclusion.
The Court also has created several exceptions where evidence will not be excluded despite deliberate police misconduct. Independent source , inevitable discovery , and attenuation of the taint , all are recognized instances in which exclusion is not required even though a Fourth Amendment violation has occurred. Exclusion is similarly not required if the illegally obtained evidence is being used only to impeach the accused. Finally, exclusion of illegally obtained evidence is not required if the prosecution can demonstrate that police officers acted in “good faith” and did not willfully violate the Constitution. In practice, these various restrictions have meant that unconstitutionally obtained evidence is frequently deemed admissible.
But what does any of this--downgrading of the warrant requirement or limitations on exclusion--have to do with the prosecution? As noted at the outset, criticism of the Court's permissive interpretation of the Fourth Amendment focuses primarily on how much discretion it affords the police. But, as will be discussed below, a straight line can be drawn from the discussion above to an increase in prosecutorial power.
