The Fourth Amendment to the United States Constitution protects criminal suspects from unreasonable searches and seizures. Generally, this means that law enforcement must have probable cause to believe that a crime has been committed before they can conduct a search of a person and his or her property.
Since the Bill of Rights was ratified more than 220 years ago, the United States Supreme Court has carved out some broad exceptions to the Fourth Amendment's protections. It did so again in June 2013, when it ruled that law enforcement officers are legally permitted to take DNA samples from individuals who have been arrested on suspicion of committing a crime. Officers may then run those samples through a database to determine whether the suspect's DNA matches evidence from any unrelated unsolved crimes.
Currently, 28 states and the federal government utilize this practice. It is expected that DNA testing will become more widespread in the wake of the Supreme Court's ruling.
Intrusion outweighed by state interests
The case, titled Maryland v. King, involved a Maryland man who was arrested on suspicion of menacing with a shotgun. During the booking process, police swabbed the inside of the man's cheek to obtain a DNA sample. They then compared that sample to DNA evidence from unsolved crimes and discovered that the man's DNA matched evidence recovered from a 2003 rape scene. He was ultimately convicted of that rape.
The man challenged the rape conviction, arguing that the search of his person violated his Fourth Amendment rights. The State of Maryland disagreed, asserting that a DNA swab is not an invasive procedure and that any intrusion into a suspect's privacy is justified by the state's interest in resolving unsolved crimes.
In a 5-4 decision, the Supreme Court agreed with the state. In reaching its decision, the majority reasoned that DNA swabs were a normal part of the booking process, much like fingerprinting a suspect and taking his or her photograph. It held that a state's interest in determining a suspect's true identity – including whether he or she had committed crimes in the past – outweighed the intrusion into the suspect's privacy.
The dissenting justices disagreed with this reasoning. They argued that taking DNA samples isn't really about identifying suspects, but about trying to link suspects – who are supposed to be presumed innocent – to prior crimes when there is not preexisting probable cause to believe the suspect might be guilty of the unrelated offense.
Impact on future cases
The Supreme Court's decision came as a surprise to many court-watchers, especially when compared to the court's ruling in Missouri v. McNeely earlier this year. In that case, the Supreme Court held that states violated the Fourth Amendment when they allowed law enforcement to take blood samples from drunk driving suspects without a warrant. In doing so, the court decided that the suspect's privacy rights outweighed the state's interest in obtaining evidence of a crime before it disappeared.
The Supreme Court's ruling means that the stakes are now even higher whenever a person is arrested. Even if there is not sufficient evidence to convict on the charge for which the arrest was made, the suspect could be linked – perhaps falsely – to past unsolved crimes. Because of this, it is import for anyone who is arrested to seek the help of an experienced criminal defense attorney. The attorney will be able to review all of the circumstances of the case to ensure the suspect's rights are well-protected.