What gives to produce such a curious judging scenario?
The majority found that the taking of a DNA swab from the cheeks of a legitimately arrested suspect in a violent case without a search warrant was a "minor intrusion" and reasonable under the Fourth Amendment for purposes of identification of the suspect:
"In light of the context of a valid arrest supported by probable cause respondent’s expectations of privacy were not offended by the minor intrusion of a brief swab of his cheeks. By contrast, that same context of arrest gives rise to significant state interests in identifying respondent not only so that the proper name can be attached to his charges but also so that the criminal justice system can make informed decisions concerning pretrial custody. Upon these considerations the Court concludes that 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."The common ground here among the Justices is the realization that DNA identification is a modern tool that should not be withheld from law enforcement officials as an essential part of their work in bringing criminals to justice. This attitude toward the lawless is essentially an old, tried and true conservative credo that concentrates on protecting society from its criminals.
A countervailing, equally old, tried and true conservative credo is that government should, to the greatest degree practicable, keep its nose out of the affairs of its citizens, which is why the law protects persons from unreasonable searches, especially in their homes, under the motto that a man's home is his castle. Search warrants are required.
This legitimate conservative doctrine has in the course of the years been extended in various ways to the body of a person and their privacy to boot.
Maryland v. King pitted TWO conservative ideals against each other:
Law and Order (i.e. bringing criminals to justice)
Property Rights (i.e. no blanket searches without warrants)
Law and Order won, but only barely.
Justice Scalia wrote a typically scathing dissent which is well worth reading. We think he is right on the law in terms of the precedents, but wrong on the era. Times change, and the law must change with the times.
The need for law and order in our modern age is, if anything, greater than it ever was, for the opportunities for criminal mischief have been greatly compounded due to greater mobility and digital tools.
To counteract ever better outfitted criminals, law enforcement must be able to access the modern tools available and necessary for its work.
At the same time, contrarily, one of the fields of law under greatest stress in our modern age, and rightly so, from a "tech" view, is the entire area of "property rights", whether this be real estate or personal privacy. There the trend is in the opposite direction, i.e. toward a greater public interest and participation in everything, and a smaller role to individual property rights, a development we see keenly in intellectual property law.
Still, one should not forget that the danger of personal violation is a strong and legitimate interest of citizens as well, especially females, and hence, it is no surprise that all three women on the court (Justices Ginsburg, Sotomayor and Kagan) found DNA swabbing of arrested individuals a violation of privacy, because it does involve a physical intrusion. All the men on the court, except for Scalia, found it "minor". And Scalia's dissent was more in the line of originalism and less along the line of women's rights. Nevertheless, this decision does have a gender element, apart from search warrant issues.
At any rate, the division of Justices in this case can be rationally understood using the above analysis.
Should law enforcement be able to determine an arrested person's DNA?
But of course, methods should be developed to make this the least invasive procedure available.
That way both conservative ideals would be honored.