how does the 4th amendment apply to traffic stops?

Answer 1

The Fourth Amendment to the United States Constitution protects against unreasonable searches and seizures. In practice, this has created a sliding scale in which the amount of suspicion a government agent (i.e. a police officer) has is weighed against the intrusiveness of the search or seizure.

At this point in time, a traffic stop must be supported by "reasonable suspicion." Reasonable suspicion means in this case that the police officer has information such that a reasonable person would conclude that a crime has been, is being, or will be committed. This is a pretty low standard of proof, as merely following any car for a short length of time will present some evidence that an officer can use to justify a traffic stop (the car will break a minor traffic law). If the traffic violation is not the ultimate purpose of the stop, it is known as a "pretext stop" (pulling someone over for a minor violation with the hope of uncovering evidence of something else).

Some exceptions have been made to the reasonable suspicion standard, such as DUI checkpoints where everyone stops, or in which random vehicles are selected (the traffic stop is considered more reasonable because it is very brief, everyone is equally subjected to it, and they've been shown to be fairly effective at combating DUI).

Once a person is stopped, he or she may be questioned briefly by the police officer and required to present proof of licensing and registration and insurance (the specific details of what is to be provided in specified under state law). If the officer feels that he or she is potentially in danger, he or she might conduct a brief "patdown" or frisk for weapons (as such searches are also deemed admissible under the reasonable suspicion standards).

At this time, the police officer will ask some questions and look into the windows of the vehicle in order to try to find anything that would give him or her justification to conduct further investigation. Whatever the officer sees or otherwise observes will be considered admissible since it is in "plain sight," but more importantly spotting anything suspicious might give rise to "probable cause," which is the next higher standard of suspicion.

Probable cause is defined as evidence sufficient that a reasonable person would believe that a crime has been committed and that the person to be searched is linked to it. An officer observing drugs or drug paraphernalia inside a vehicle through the window would have probable cause to search the vehiclefor additional evidence. Probable cause could also be obtained by the behavior or statements of the suspect.
(EDIT NOTE: I originally had "responsible" instead of "linked to it" above. After reading the mikeysco answer, I re-read my own and realized that there was indeed a flaw. Thanks, mikeysco, for the careful read!)

Absent probable cause, a police officer will only be able to search the vehicle or driver if he or she has permission. Unfortunately for suspects, most of them give permission without even thinking about it. If you've ever seen an episode of "Cops" you've probably heard a police officer asking someone if he or she could search a suspect's vehicle. In almost all circumstances that suspect will say yes, in the mistaken belief that showing you have nothing to hide will cause a police officer not to bother.

This brief overview is not intended to be exhaustive, as the law regarding traffic stops is very detailed and constantly evolving. The main thing to remember is that a traffic stop requires reasonable suspicion, while a search requires probable cause.

Answer 2

For the most part, Federal law and most state laws allow an officer to search your car under 3 circumstances: 1) consent, 2) probable cause and 3) you committed a felony. Consent is when an officer asks for your permission to search your car. Probable cause is when the officer believes there is some evidence (smell of drugs in car or surveillance of goods being loaded in car) that a crime has been committed. The Patriot Act probably expanded on what action might be considered probable cause. And when you get arrested for a felony, officers can search your car (for safety purposes) before towing it away.

Answer 3

In a traffic stop, the cop already has established reasonable cause.
He will state why they pulled you over and then determine from your actions whether or not a further search of your vehicle is warranted (ie if he pulls you over for suspicion of being under the influence, that is reasonable cause to search your vehicle for any open containers of alcohol, or drugs).

Answer 4

You do not need probable cause to search a vehicle, consent, plain view, furtive movements are just a few that do not require PC. also a hit from a drug dog will give you the right to search

Answer 5

No because it says correct of the human beings which does no longer contain unlawful extraterrestrial beings. the human beings who write those regulations recognize what to write down. they are attentive to the 4th modification and are not likely to write down a regulation that anybody might want to defeat with the 4th modification citation.

Answer 6

THE 4TH PERTAINS TO "ILLEGAL SEARCH AND SEASURE" THEY CAN CLAIM IT WAS JUSTIFIED UNDER THE NEW PATRIOT ACT, IF THEY JUST TELL YOU THEY WANT TO SEARCH YOUR VEHICLE YOU CAN DEMAND THEY GET A SEARCH WARRANT, BUT MOST LIKELY THEY'LL KEEP YOU UNTIL THEY GET ONE!! IF THEY DO DETAIN YOU YOU CAN DEMAND THEM TO PUT YOU UNDER ARREST AND IF THEY'RE FOUND TO BE UNJUSTIFIED YOU CAN CLAIM "FALSE ARREST"