Last week, the US Supreme Court heard oral argument on a DUI case out of Missouri. The issue is whether police officers can draw blood from DUI suspects without a warrant. Missouri allows it, but of course, the Fourth Amendment is the supreme law, so if SCOTUS says it's not ok, it won't be ok.
Missouri's claim is that exigent circumstances justify not following the warrant requirement. Exigency is a well-established exception to the warrant requirement. Like if cops hear gunshots or screams from inside a home, they don't have to dither around and wait for a magistrate to sign off before they can enter. (I'm ok with that one.) Or if it sounds like the suspected druggies are flushing their stash down the toilet. Or if the suspected crime scene is a car that can drive off. Lots of circumstances have been found to be exigent enough that cops needn't wait for a warrant, so it's no surprise that Missouri would think blood alcohol levels dissipating over time would qualify as exigent.
But a funny thing happened during the argument. The attorneys and justices kept coming back to the question of how long it would take to get a warrant: 20 minutes? half an hour? two hours? They were at times trying to parse how much time is reasonable to make cops wait to try to get a warrant. And all I could think was how the folks who wrote the Fourth Amendment and/or insisted on adding it to the Constitution before ratifying that document would laugh in wonder at the idea that we could get a warrant in under two hours. The idea that a prosecutor and magistrate could be reached and act on a warrant application in 20 minutes would sound like science fiction to people from an era when the magistrate only made it to your town once every three months. So the idea that having to wait a whole hour or two is so unbearably inconvenient that it demands ignoring the warrant requirement would have to be offensive to those original proponents of the Fourth Amendment, wouldn't you think?