In all US States, everyone who is arrested has been required to provide DNA by means of a mouth swab for many years. Some people are threatened by this (Ramirez cartoon above) but my opinion apparently differs from some conservatives. I'm not ALWAYS that conservative or so it seems. That may be because of my experience with DNA evidence as a tool of law enforcement, in the context of the Fourth Amendment.
When you're arrested and placed into a jail, you are subjected to a thorough search including a 'cavity search'. It's invasive, but necessary for the protection of both custodial officers and other inmates. Adding a DNA swab is far less invasive than that.
DNA evidence has become a powerful tool for law enforcement officers to hold the guilty accountable and also to dismiss charges against people who are not guilty. The sword swings both ways. News accounts are replete with examples of people doing time in prison, as it turns out wrongfully. The evidence used to convict is re-examined using DNA and they are released because they're innocent.
In Maryland v King, the US Supreme Court reaffirmed the right of the government to identify people through the use of a DNA sample, in much the same way as finger prints and photographs have been collected over the years.
MARYLAND v. KING
CERTIORARI TO THE COURT OF APPEALS OF MARYLAND
No. 12–207. Argued February 26, 2013—Decided June 3, 2013 After his 2009 arrest on first- and second-degree assault charges, re-spondent King was processed through a Wicomico County, Maryland facility, where booking personnel used a cheek swab to take a DNA sample pursuant to the Maryland DNA Collection Act (Act). The swab was matched to an unsolved 2003 rape, and King was chargedwith that crime. He moved to suppress the DNA match, arguing that the Act violated the Fourth Amendment, but the Circuit Court Judgefound the law constitutional. King was convicted of rape. The Mary-land Court of Appeals set aside the conviction, finding unconstitutional the portions of the Act authorizing DNA collection from felony arrestees.
Justice Kennedy wrote the Court's opinion (5-4 decision)Held: When officers make an arrest supported by probable cause to holdfor a serious offense and 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 Scalia (arguably the most conservative member of the court) dissented and was joined in that dissent by the most liberal members of the court: Justice Ginsburg, Justice Sotomayor and Justice Kagan. They dissented along Fourth Amendment grounds and if you have any interest, you should follow the link (above) and read their reasoning.