The nation's highest court on Wednesday considered whether police should be able to forcibly draw the blood of a motorist without a warrant. Supreme Court justices heard oral arguments in the case of Missouri v. McNeely to decide whether Tyler McNeely's constitutional rights were violated when he was taken to a hospital for a blood draw after a state patrolman accused him of driving under the influence of alcohol (DUI) in October 2010.

"The issue in this case is whether the state may stick a needle in the arm of everyone arrested on suspicion of drunk driving without a warrant and without consent," McNeely's lawyer, Steven R. Shapiro, argued. "Missouri's answer to that question is yes, even in routine DWI cases like this and regardless of how quickly and easily a warrant could be obtained."

Prosecutors insist obtaining a warrant takes too much time. Since, they argue, evidence of alcohol is purged from the body over time, police were right to cite "exigent circumstances" to bypass the Fourth Amendment requirement to have a independent judge review the evidence before authorizing the blood draw. Several justices seemed skeptical about the claim.

"So how can it be reasonable to forego the Fourth Amendment in a procedure as intrusive as a needle going into someone's body?" asked Justice Sonia Sotomayor. "I say this because breathalyzers in my mind have a much different intrusion level. They don't intrude into your body."

Many states have a program where judges are on standby to receive warrant applications over the phone for DUI cases. In these programs, warrants can be issued very quickly.

"The virtue of it is this man or woman is trained to listen to policemen and others say things and try to pin him down a little bit and make an independent judgment," Justice Stephen G. Breyer said. "So -- so why would it take more than 5 minutes? .... It would make it less likely that people who are really innocent in fact have this happen to them and so forth."

Prosecutors argued such a system would not be feasible with all the paperwork and delays inherent in the legal system. Even if it were possible to obtain a speedy warrant, the protection it offered would be meaningless.

"I think if we were to the point where we were approving search warrants in three minutes, it would essentially be a rubber stamp," Jackson, Missouri prosecuting attorney John N. Koester Jr said.

Twenty-five states currently prohibit warrantless blood draws, fifteen of which joined this case to formally oppose the prosecution's argument that the warrant requirement is just too burdensome in rural jurisdictions. Justice Antonin Scalia suggested setting a precedent that applied nationwide based on current limitations could be a problem if technology advances to make it easier to present evidence to a judge in rural areas. He also wondered whether the warrant has become something of a formality that holds little meaning in DUI cases.

"In these DUI cases it's always going to be the same thing," Scalia said. "The policeman is going to say, well, you know, his breath smelled of alcohol; we gave him the walk a straight line and turn around test, he flunked it; he couldn't touch his nose with his index finger. What is the impartial magistrate possibly going to do except to say, hey, you know, that's probable cause."

The defense answered that warrants generally are not turned down, regardless of the subject matter.