According to the Nevada Supreme Court, this warrantless blood draw is in clear violation of the constitution because of the Fourth Amendment, which protects individuals from unauthorized search and seizure. The Court felt that the existing law put in place procedures that eroded the foundations of the Fourth Amendment, an important protection that needed to be reasserted.
The Nevada Supreme Court went on to note that in other states with implied consent laws, drivers are given the choice to refuse to submit to a chemical test. This refusal usually results in the loss of driving privileges or payment of a fine, but it does permit some degree of choice. In Nevada, no such choice exists. Drivers are simply required to submit to a test to determine their level of impairment when instructed to by officers, warrant or no.
Experts say the ruling will lead to big changes in Nevada. Starting now, drivers will be able to simply tell an officer “No.” This means that police officers will have to start securing warrants for those cases where they suspect impaired driving or get truly voluntary consent from the driver.
Source: “Nevada high court strikes DWI implied consent law,” by William Helbling, published at Jurist.org.