Authorities can be very aggressive in their DWI enforcement efforts. It is very important that a DWI suspect's constitutional rights are properly protected when it comes to such enforcement efforts.

Recently, the Missouri Supreme Court reached a decision in a case that gave rise to some DWI-enforcement related constitutional questions.

The case involved a man who was stopped under suspicion of DWI in 2010. Allegedly, police asked the man to submit to a breath test and the man refused to submit to the test. Reportedly, a police officer then ordered that a blood test be done on the man. This order was reportedly made without a warrant. The question that came before the Missouri Supreme Court was whether this warrantless blood test was constitutional.

The Missouri Supreme Court ruled that this warrantless blood test was unconstitutional. In its decision, the court said that blood tests of an unwilling DWI suspect require a warrant, except when special circumstances are present. The court further said that the fact that blood alcohol levels go down over time after a person stops drinking does not, on its own, constitute such a special circumstance.

The court ruled that no special circumstances were present in this case and thus that the warrantless blood test violated the man's constitutional rights.

This recent decision by the Missouri Supreme Court illustrates a couple of points. The first point is that there are constitutional limits to the methods that authorities can use in their DWI enforcement efforts. The second point is that the exact location of these limits sometimes ends up being determined through court decisions.

Source: St. Louis Post-Dispatch, "Mo. court rejects warrantless DWI blood test," Jan. 17, 2012