Given that U.S. Supreme Court Justice Samuel Alito has described a case ruled on by the Court earlier this week as “the most important criminal procedure case that this court has heard in decades,” the matter obviously merits a bit of discussion. Following is a summary of the seminal federal appeals case and its outcome.

Several years ago, a man was arrested on an assault charge in Maryland. As provided for under that state’s law, he was compelled to submit DNA following his arrest. Police officers then uploaded that DNA into a national database, where it matched with DNA collected from an unsolved rape case. The suspect was convicted of that crime.

A state appellate court reversed the conviction on the ground that police had no reasonable cause to suspect the man of having committed another crime when they arrested him for assault. The court held that a cheek swab was constitutionally barred in the absence of a warrant.

That was the backdrop for the Court’s ruling this past Monday, in which a 5-4 majority upheld the man’s conviction, with Justice Anthony Kennedy stating that taking DNA following an arrest for a “serious” crime is akin to nothing more than fingerprinting a suspect at the police station. It is, noted Kennedy, both necessary and permissible under the Fourth Amendment.

Not all the justices saw it that way, with Justice Antonin Scalia saying that compelling a suspect to submit to a DNA swab at the police station and then running that DNA through databases in an attempt to solve other crimes equates to a “suspicionless” search that cannot be countenanced under the Fourth Amendment.

Twenty-five other states already have a law on the books that is similar to Maryland’s, and the Court ruling is expected to increase that number substantially.

As Justice Scalia noted, though, there will be a price to pay for the expanded use of DNA in terms of intrusions on privacy and mistakes that will be made.

“The proud men who wrote the charter of our liberties would not have been so eager to open their mouths for royal inspection,” he said following the ruling.

Source: USA TODAY, “Supreme Court OKs DNA swab of people under arrest,” Richard Wolf, June 3, 2013