Yesterday, the Supreme Court decided two Fourth Amendment cases. The results were mixed. In one case, the Court protected an individual from an unreasonable search. But in another case, the Court again watered down Fourth Amendment protections in the name of the War on (Some Classes of People Who Use Some) Drugs.
The facts of the first case are relatively straightforward. The police had a warrant to search an apartment, but searched the assumed resident a mile away from the apartment after tailing him in a car for several minutes. In a 6-3 opinion written by Justice Kennedy, the Court held that the search violated the Fourth Amendment. The warrant, Kennedy persuasively reasoned, covers only the immediate vicinity of the apartment, and there were no exigent circumstances (such as an immediate flight risk or the treat of violence) that would justify the warrantless seizure of items from a person not in the vicinity of the apartment. The most interesting part of this case is the vote lineup. Stephen Breyer, a Democratic appointee but often conservative on civil liberties issues, voted to uphold the search, joined by Justice Thomas and the Court's most consistent reactionary, Samuel Alito. However, Justice Scalia (who has a libertarian streak on civil liberties issues Alito lacks), along with Justice Kennedy and Chief Justice Roberts, joined the remaining Democratic appointees to rule that the search was invalid.
The Court's other Fourth Amendment ruling yesterday was unanimous, which doesn't make it persuasive. The case involved a search of an automobile for drugs in which probable cause was established by a drug-sniffing dog. For such searches to be reasonable requires that dogs actually have a reliable record of distinguishing between automobiles that contain drugs and those that do not—if the sniffing produces essentially random results, they cannot be used as probable cause for a search. The facts of this case provided good reason to believe that the dog used in this case was not reliably able to detect drugs. In the search that led to the suspect's arrest and conviction, the search found drugs—but not the drugs the dog was trained to detect. In a subsequent search of the same defendant, the dog's behavior indicated the presence of drugs, leading to another search that yielded nothing.
Given that the dog sniffing that allegedly justified the searches produced two false positives out of two searches, the Florida Supreme Court reasonably concluded that the fact that the dogs were trained and certified was not adequate to allow the dogs to provide probable cause for a search. The state, the Florida court held, had to provide additional evidence, including the performance of the dog in the field. If dog sniffing did not produce reliable results, it could not be used to establish probable cause.
The Supreme Court, however, rejected this requirement for better evidentiary safegaurds. A dog's field performance, Justice Kagan argued for the Court, is not a perfect test of the reliability of a search, and may understate false negatives and false positives. This is true, but of course the same can be said of the state's certification process, which it would be foolish to accept on blind faith. The Florida Supreme Court reasoned, correctly, that more evidence is better than less, and the state needs to provide evidence of how drug-sniffing dogs perform in the field, not just in controlled settings in which independent agencies will have strong incentives to certify that dogs are able to identify drugs.
The fact that the Supreme Court was, in the second case, to the right of the state court highlights something important about the Court: while the Court has several of the most conservative judges of the last century, it lacks even a single strong civil libertarian in mold of William O. Douglas or Thurgood Marshall. As Justice Kagan speaking for the Court in this case reminds us, President Obama chose not to fill this void.