What constitutes an illegal search?

Answer 1

A search by law enforcement that is not supported by at least articulable reasonable suspicion. See: http://en.wikipedia.org/wiki/Terry_v._Ohio

A search that takes place without a warrant and without probable cause. Probable cause requires a reasonable articulable suspicion that a crime has been committed or is about to be committed. It is more than a mere hunch. For more information, see the related links below.

Answer 2

In the US, an illegal car search is when a police officer has no probable cause to conduct a search of a person's vehicle. Probable cause for a search would be, for example, if the police officer stops a car for a traffic violation. If the officer is asking the driver for license and registration and sees a firearm on the passenger seat and the driver will not answer a simple question about the firearm, there is no question that a search can begin. Another example would be an officer stopping a car for a traffic violation and the officer knows that car is listed as a stolen vehicle.

Answer 3

Under the 4th amendment an arbitrary search of your car without a warrant, your permission, or a valid reason is illegal. Yet, there are some limited situations that a search can take place without a warrant or permission. The courts give police more leeway in searching cars compared to a residence. This is because under the automobile exception the courts have recognized that individuals have a lower expectation of privacy when driving a car than when they are at home. The Supreme Court has ruled that a warrantless police conduct may comply with the 4th amendment as long as its reasonable under the circumstances. The officer must have probable cause to believe there is evidence of a crime in your car and they reasonably believe a search is necessary for their own protection ( a hidden weapon). If you are arrested a search is conducted related to the arrest such as illegal drugs. Cars can be stopped for violating traffic laws and if the reasons for the stop is a minor traffic offense like speeding the officer wouldn't likely be permitted to search your car without more reason. If a car is impounded they have the right to do a search and it can be comprehensive as they want. The reason why the car was towed and impounded is not important, but they can't tow and impound a car for the sole purpose of a search.