The 4th Amendment protection against "unreasonable searches and seizures" is a basic protection against governmental tyranny. During the colonial period in America, British troops were provided with documents that allowed them to search without warrants. The 4th Amendment abolished that practice. However, police misconduct regarding searches continued into the twentieth century. In Weeks, 1914, the Supreme Court excluded from federal courts any evidence gained by an illegal search. In Mapp, 1961, this "exclusionary rule" was extended to all courts in the United States. Evidence gained by an illegal search was termed "inadmissible" by the Court. Broad rulings by the Courts are usually subject to repeated tests, and so, too, was the exclusionary rule. In the years after Mapp, law enforcement officials attempted to chisel away at the ruling, arguing that it was too broad. Did the rule apply under all circumstances? Were there no exceptions to the rule? Reasonable people understood that the rule could not remain absolute, even if it upheld the right to be free of unreasonable interference by the government.
In 1979, Sandra Boulware's badly beaten and burned body was found in a vacant lot in Boston. Her boyfriend, Sheppard, was questioned in connection with the murder. Since they had found bloodstains in a car Sheppard had borrowed, police believed they had probable cause to obtain a warrant to search his house.
The affidavit for the search warrant was properly completed. However, the detective leading the investigation was unable to find the proper kind of search warrant form, and instead used one intended for drug searches. The detective did not include a list of specific items for which the police wanted to search. He pointed out this omission when he presented the materials to a judge for approval. The judge signed the warrant and told the detective that the court would make the necessary changes in the document and attach the list of items to the amended warrant. The changes were not made and the defect was discovered during the trial.
Using the warrant "in good faith"—that is, believing the warrant to be proper—the police searched Sheppard's home and found Sandra Boulware's bloodstained clothing. Sheppard was prosecuted and convicted, and the clothing was used as evidence in his trial. Sheppard's lawyers protested the introduction of that evidence. They argued that because the warrant was "faulty," the fruits of the search were tainted. Therefore, the evidence should have been "excluded" from testimony because of the illegal nature of the search.
The Court was asked to re-examine the exclusionary rule as it had been applied since 1961. Was evidence admissible if it was gained by a search based on a warrant that had technical mistakes? Did the exclusionary rule prevent the use of such evidence if the judge who issued the warrant, and not the police, made those mistakes? Should a convicted murderer be set free because of a "technical error" in a warrant? Or was the fact that the police had acted "in good faith" sufficient to prevent a strict reading of the exclusionary rule?
For Massachusetts: The exclusionary rule was never intended to extend to clerical errors or the incorrect completion of search warrants and other forms. The process of law enforcement is difficult enough without invalidation by the courts of vital police work because of minor technicalities. The fact is that a judge approved a warrant based on adequate probable cause. The intent and substance of the State's proceeding observed the spirit of the 4th Amendment. Sheppard was the accused and under suspicion. The evidence in his apartment was critical to the prosecution. The detective and the judge both understood that corrections were needed to make the search warrant acceptable under 4th Amendment guidelines. Sheppard's rights were observed and his conviction should not be overturned.
For Sheppard: There is no excuse for careless police work; police officers must be professional. Allowing police to hide their carelessness behind declarations of "good faith" could open the door to all sorts of police misconduct. The police must follow the letter, not just the spirit, of the 4th Amendment. In this instance they did not. Due process works only when police "do things right." Unfortunately, not all police are properly versed in their craft. Ultimately, the Court must adhere to the axiom stated long ago by Justice Cardoza: "When the constable blunders, the accused person must be set free."
Justice Byron White delivered the opinion of a 6–3 majority that upheld Sheppard's conviction. White wrote that the Court's understanding of the 4th Amendment did not require the exclusion of the evidence in this case. The exclusionary rule should not be applied when the officer conducting the search has acted with the reasonable belief that he was following proper procedures. The detective believed that the judge had made the warrant "correct." As Justice White said, "The officer took every step that could be reasonably expected of him."
White's opinion noted that since the judge, and not the police, had "made the critical mistake," the police were free of any intent to violate Sheppard's rights. "Suppressing the evidence because the judge failed to make all of the necessary changes and clerical corrections, despite his assurance that the changes would be made, will not serve the deterrent function of the exclusionary rule." The exclusionary rule, in other words, is meant to deter police from violating people's rights.
With this decision, a technical error in warrants or processes would not result in "tainted evidence"—that is, evidence gained in a search with a defective warrant—if the officers acted "in good faith" and with no intent to infringe upon anyone's rights. The decision to limit the exclusionary rule paralleled the Court's decision in Nix v. Williams, 1984, and United States v. Leon, 1984. Exceptions to the exclusionary rule thus had the effect of limiting the power of the rule. Civil libertarian activists assailed the decision as a "serious erosion" of the exclusionary rule. Prosecutors labeled the decision "reasonable."