The majority’s opinion, written by justice Anthony Kennedy, likened the practice to fingerprinting and photographing, both crucial measures already practiced by law enforcement to help them identify and convict suspects. The decision will help police identify criminals who have been tied to multiple crimes and may even exonerate individuals who are wrongfully behind bars.
However, the opposing justices see the measure as an drastic increase in police powers and believe that allowing DNA samples to be extracted upon arrest for violent crimes will lead to the same being allowed for nonviolent offenses. Prior to this decision, it has been normal practice to collect DNA samples after a criminal is convicted of an offense rather than at the time of arrest.
More than half of the states and the federal government already allow DNA swabbing at the time of arrest. Of course for a person’s DNA to be of any use in court, investigators will have to have found a matching sample at the scene of a crime to use as evidence.