Constitutional protections do not forbid police from taking DNA samples from those arrested for serious crimes, according to the Supreme Court in its 5-4 decision Monday in Maryland v. King .

If someone is arrested on suspicion of having committed certain felonies (not lesser crimes), Maryland law authorized police using a cotton swab to take a DNA sample. Police would then check to see if that DNA matches unsolved crimes in other cases.

All 50 states allow taking DNA from people who are convicted of felonies, after they have been afforded all their due-process rights and been found guilty beyond a reasonable doubt. The difference here is taking DNA after an arrest for a serious crime, but before any determination of conviction in court. There are 28 states with laws like Maryland’s.

The Maryland Court of Appeals (that state’s highest court) struck down the Maryland statute in a divided decision, holding that the DNA sample violating the arrested person’s Fourth Amendment right against “unreasonable searches and seizures.” Today the Supreme Court reversed in a decision written by Justice Anthony Kennedy.

Kennedy noted that a cotton swab is painless and less invasive than a needle for drawing a blood sample. They majority considered those factors an element of whether this “search” is “reasonable.” He added, “When faced with special law enforcement needs, diminished expectations of privacy, minimal intrusions, or the like, the Court has found that certain general, or individual, circumstances may render a warrantless search or seizure reasonable.”

The majority cited precedent to set forth the general framework that certain:

“… circumstances diminish the need for a warrant, either because the public interest is such that neither a warrant nor probable cause is required, or because an individual is already on notice, for instance because of his employment, or the conditions of his release from government custody, that some reasonable police intrusion on his privacy is to be expected.”

Kennedy explained:

“Even if a warrant is not required, a search is not beyond Fourth Amendment scrutiny; for it must be reasonable in its scope and manner of execution. Urgent government interests are not a license for indiscriminate police behavior. To say that no warrant is required is merely to acknowledge that rather than employing a per se rule of unreasonableness, we balance the privacy-related and law enforcement-related concerns to determine if the intrusion was reasonable.”

Kennedy noted that the Court has always held that if you are arrested, police can demand to know your name, address, and Social Security number to identify you. The majority regarded DNA testing as another form of identification. It’s also one that is also relevant to determining past criminal history, noting that police typically run background checks on people they arrest seeking precisely that information.

Police also have concern to know whether the person they take into custody is especially violent or mentally ill. The Court reasoned that it’s vitally important that police “For these purposes officers must know the type of person whom they are detaining, and DNA allows them to make critical choices about how to proceed.” Courts have already allowed police to take notice of marking like gang tattoos.

The Court further reasoned, “DNA identification represents an important advance in the techniques used by law enforcement to serve legitimate police concerns for as long as there have been arrests … Law enforcement agencies routinely have used scientific advancements in their standard procedures for the identification of arrestees.” The best-known example was when police started fingerprinting.

The Court regarded it as significant that Maryland law only allows the information to be used for identification, and requires the information’s destruction if nothing comes up.

The Supreme Court concluded:

“DNA identification of arrestees is a reasonable search that can be considered part of a routine booking procedure. When officers make an arrest supported by probable cause to hold for a serious offense and they bring the suspect to the station to be detained in custody, taking and analyzing a cheek swab of the arrestee’s DNA is, like fingerprinting and photographing, a legitimate police booking procedure that is reasonable under the Fourth Amendment.”

Justice Antonin Scalia dissented in an unusual alliance, joined by the three most liberal members of the Court, Justices Ginsburg, Sotomayor, and 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. That prohibition is categorical and without exception; it lies at the very heart of the Fourth Amendment. Whenever this Court has allowed a suspicionless search, it has insisted upon a justifying motive apart from the investigation of crime. It is obvious that no such … motive exists in this case.”

Scalia’s dissent went back to the adoption of the Constitution, noting that the Framers objected to the British use of “general warrants,” authorizing arrest or detention not focused on a particular alleged crime. He considered it a critical limitation that whenever the Court has upheld searches without suspicion, that it was never looking for general evidence of other crimes.

Scalia specifically noted that the DNA test results are not put into the matching system for a couple days. Thus, he reasoned, it has nothing to do with properly identifying the person in custody, and is instead a wide-ranging investigation for previous crimes.

Noting that the Maryland statute makes it a crime to misuse the DNA information, Scalia adds sarcastically, “I hope the Maryland officials who read the Court’s opinion do not take it seriously. Acting on the Court’s misperception of Maryland law could lead to jail time.”

Scalia concludes:

“The Court disguises the vast (and scary) scope of its holding by promising a limitation it cannot deliver… Make no mistake about it: As an entirely predictable consequence of today’s decision, your DNA can be taken and entered into a national DNA database if you are ever arrested, rightly or wrongly, and for whatever reason…. Today’s judgment will, to be sure, have the beneficial effect of solving more crimes; then again, so would the taking of DNA samples from anyone who flies on an airplane (surely the [TSA] needs to know the “identity” of the flying public), applies for a driver’s license, or attends a public school… But I doubt the proud men who wrote the charter of our liberties would have been so eager to open their mouths for royal inspection.”

Breitbart News legal columnist Ken Klukowski is a fellow with the American Civil Rights Union and on faculty at Liberty University School of Law.