If South Dakota police pull you over because they suspect you’re driving under the influence, you can usually expect a field sobriety test and a breathalyzer. If you fail those tests, you might be taken to the station for a urine or blood test. But do you have to take it?

This is where the “implied consent” comes in. This is an area where laws across the country are rapidly being questioned – and changing.

Forced urine tests in South Dakota made headlines this summer when a case involving evidence extracted from an involuntary urine test raised questions about the practice in general. Tests to determine blood alcohol content (BAC) or the presence of drugs are generally justified under implied consent laws.

Implied consent describes the assumption that drivers – simply by operating a vehicle – consent to tests to determine their BAC or presence of marijuana or other drugs. Although laws vary across the country, implied consent typically covers, at a minimum, breathalyzers and field sobriety tests.

Urine and blood tests are more controversial.

In 2014, the South Dakota Supreme Court ruled that the state’s implied consent law doesn’t cover blood tests and that law enforcement would need to obtain a warrant before taking the blood of someone suspected of DUI. This is in line with a recent U.S. Supreme Court ruling that draws the line between a breath test and blood test. Blood tests, the court ruled, require a warrant, but breath tests do not.

This ruling just came down a few months ago, however, so it’s unlikely every law enforcement division across the country has adopted new protocol for DUI arrests. With this area of the law currently in flux, an attorney can help you make sure your rights are protected in the event of a DUI arrest.