http://news.yahoo.com/police-now-col...192600381.html
Rather than serving as a tool to verify someone's identity, they argue that it's really a backdoor to circumvent the Fourth Amendment's protection against "unreasonable searches." Police had no reason to suspect King had been involved in that rape, yet they used his arrest and DNA to charge him for an unrelated crime.
The case did not break on the usual ideological lines. In a withering dissent, Justice Antonin Scalia, joined by three liberals on the bench, said it "taxes the credulity of the credulous" to suggest DNA testing is really about determining someone's identity:
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. [SCOTUSBlog]
The court did not rule on specific limits for conducting pre-conviction sampling, which is another major point of contention.
The court said it can only be done in the case of "serious" crimes. Yet that term is subjective, a point Scalia lambasted while arguing that the majority had "disguise[d] the vast (and scary) scope of its holding by promising a limitation it cannot deliver."
"Make no mistake about it: because of today's decision, your DNA can be taken and entered into a national database if you are ever arrested, rightly or wrongly, and for whatever reason," he said.