When can a mobile vehicle search be conducted without a warrant?

A mobile vehicle search can be conducted without a warrant if there is probable cause to believe that the vehicle contains evidence or contraband. This principle is rooted in the Fourth Amendment of the U.S. Constitution, which protects against unreasonable searches and seizures. The rationale is that vehicles are inherently mobile, meaning that evidence could be easily removed or destroyed if an officer were to wait for a warrant. Probable cause must be based on facts or circumstances within the officer's knowledge that would lead a reasonable person to believe that a crime has been committed or that specific items connected to a crime are currently located in the vehicle.

The other options do not sufficiently meet the legal standard required for a warrantless search. For instance, merely parking on private property does not negate the expectation of privacy or establish probable cause for a search. Similarly, just observing someone acting suspiciously near a vehicle or a driver's nervous demeanor during a traffic stop does not provide the factual basis needed to justify a search without a warrant. These scenarios may raise an officer's suspicion, but they do not equate to the strong belief necessary for probable cause.