On the road, little traffic violations occur all of the time. People lose track of their speed, they may forgot to use their turn signal or any other number of violations. One day, you are speeding along an Arizona highway and the next thing that you know there is flashing lights behind you. On a good day, this should result in nothing more than a ticket. What happens if the cop decides to search your car and finds something else?
The Fourth Amendment protects you against unlawful searches and seizures. Now, on one hand, you do have a lower expectation of privacy when in a car. In order for an officer to search a vehicle without a warrant, he or she must have a reason. It has to be under reasonable circumstances.
Now, if you give consent for the officer to search the car, then he or she can search it. The officer has to have probable cause to believe that there is criminal evidence within the vehicle. For instance, if he or she can see drug paraphernalia in the open or if he or she can smell alcohol in your vehicle, it may constitute as probable cause. In addition, if there is any reason that the cop believes he or she has to protect his or herself against a hidden weapon, searches are legal.
If the cops pull you over as a suspect in a crime and they arrest you for that crime, then he or she can search for evidence related to the arrest.
None of the above information is meant to be legal advice. It is for informational purposes only.