Appeals are a key part of the criminal justice process. After all, with liberty or even someone’s life at stake, it’s important to have the opportunity for review, to make sure the judge or jury got the law and facts right.

Of course, very few cases go all the way up to the U.S. Supreme Court. But there is currently a Missouri criminal appeal that has risen all the way there. The case is Missouri v. McNeely and it concerns a Fourth Amendment challenge to mandatory blood draws in drunk-driving investigations.

The facts of the case are that a Missouri driver was pulled over and failed a field sobriety test. The driver refused to take a breathalyzer test. The police officer then made the driver submit to a blood draw, despite the absence of a search warrant and lack of consent to the search.

The potential ramifications of the case go well beyond drunk-driving cases. This is because the heart of the issue is the strength of the Fourth Amendment’s protections against unreasonable search and seizure. One of these fundamental protections, as understood by the courts, has been the need for law enforcement to obtain a search warrant before it executes a search of someone’s person or property.

To be sure, there are recognized exceptions to this requirement, such as exigent circumstances. But the general rule still stands, that police officers must articulate reasonable grounds for suspicion (also called probable cause) to a judge in order to get a search warrant.

By any standard, sticking a needle in someone’s arm to draw blood against his or her will is a very intrusive procedure. The Supreme Court’s ruling in Missouri v. McNeely is therefore likely to say a lot about just how far Fourth Amendment protections extend.

Source: “Missouri v. McNeely,” SCOTUSblog