On Monday, the Supreme Court upheld Maryland’s DNA Collection Act, which allows law enforcement officials to collect DNA samples on anyone they arrest for a serious crime.

In the case, Maryland v. King, Alonzo Jay King, Jr. had been arrested for assault after pointing a shotgun at a group of people. Police took a DNA sample from King, and four months later, after the sample had been sent off to a national crime database, DNA evidence linked King to an open rape case from 2003.

King was tried and convicted for rape based on that evidence. He appealed, and Court of Appeals of Maryland ruled that DNA collected under the Maryland law constituted an unconstitutional warrantless search. Maryland then appealed to the Supreme Court, which heard the case early this year.

Justice Anthony Kennedy wrote the majority opinion, joined by Chief Justice John Roberts and Justices Clarence Thomas, Stephen Breyer, and Samuel Alito. In it, he reasoned that DNA testing is similar to fingerprinting and photographing — all legitimate police booking procedures. An inner-cheek swab, he wrote, is a relatively non-invasive procedure, and the DNA is only tested for identification purposes — and does not reveal any medically relevant information.

Justice Antonin Scalia wrote a dissenting opinion, joined by Justices Ruth Bader Ginsburg, Sonia Sotomayor, and Elena Kagan. “The Fourth Amendment forbids searching a person for evidence of a crime when there is no basis for believing the person is guilty of the crime or is in possession of incriminating evidence,” he wrote.

The case was the topic of the April issue of Supreme Court Debates, DNA Testing of Arrestees, which includes background information on the issues involved and detailed the arguments for both sides.