Prosecutors in Missouri, supported by the federal government, asked the Supreme Court Wednesday to rule that the police do not need warrants to obtain blood samples in drunken-driving investigations, says the New York Times. But there seemed little enthusiasm among the justices for that categorical approach, so the argument turned instead into a search for a middle ground that would take account of the practical realities of roadside stops, body chemistry and the administration of justice in the digital age.

The natural dissipation of blood alcohol means that time is of the essence when people suspected of drunken driving are pulled over and refuse to consent to a breath test. Obtaining a warrant takes time. Yet several justices expressed discomfort with what Chief Justice John G. Roberts Jr. called the “pretty scary image” of government-sanctioned bodily intrusions involving needles. The case arose from the arrest of Tyler G. McNeely, pulled over for speeding on a Missouri highway. He seemed drunk, performed poorly on a field sobriety test and was arrested. He refused to take a breath test or consent to a blood test. One was performed anyway, about 25 minutes after he was pulled over, and it showed a blood alcohol level of 0.15 percent, almost twice the legal limit. The state suppressed the evidence.