Before stopping a vehicle, police must have reasonable suspicion that the stop will reveal evidence of a criminal or traffic offense. In order to search a vehicle or its occupants, they must have probable cause, which is subject to a higher level of scrutiny than reasonable suspicion. The Fourth Amendment guarantees these rights. A recent court case addressed whether police in a state where marijuana remains illegal may search a vehicle solely because of license plates from a state where it is legal. While the district court found that no actionable violation occurred, an appellate court found that this was a violation of the Fourth Amendment. Vasquez v. Lewis (“Vasquez I”), No. 5:12-cv-04021, mem. order (D. Kan., Nov. 26, 2014); No. 14-3278 (“Vasquez II”) (10th Cir., Aug, 23, 2016).
Defendants may move to suppress evidence obtained in violation of their Fourth Amendment rights in criminal cases. Many important decisions restricting law enforcement’s ability to conduct warrantless searches have originated from such motions. Another way to establish that a particular act or practice violates constitutional rights is through a civil lawsuit for violations of civil rights by a government agent under 42 U.S. § 1983.
It is important to note that the Vasquez rulings arise from a civil complaint, not a criminal prosecution. The burden of proof here was on the individual driver to prove that a violation occurred, rather than on the state to prove that a crime was committed. While the appellate court found that the officers violated the plaintiff’s Fourth Amendment rights, it remains to be seen whether future courts will consider this binding or persuasive precedent for criminal defendants making a similar argument.