The Fourth Amendment is one of the most important protections that Americans have against police overreach. A bulwark of the Fourth Amendments is its requirement that police get a warrant before searching for evidence of a crime.
But the warrant requirement is not absolute. In fact, there are six exceptions to it that police regularly use to invade people's privacy and search for evidence of a crime.
1. The Suspect's Consent
The most common way for police to get around the protections afforded by the Fourth Amendment is to get the suspect's consent to a search. The rights provided by the Fourth Amendment need to be invoked. Giving your consent to a police search lets those rights fall away and gives police the power to do whatever they want without fear of violating your rights.
Also known as the exigent circumstances exception to the warrant requirement, police don't need a warrant to search for evidence that will likely be destroyed or that can be discovered while responding to a legitimate emergency.
The reach of this particular exception is surprising, though. Police use it to justify conducting a breath test or a blood test of suspected drunk drivers – a search for a DUI crime – because blood alcohol content (BAC) slowly dissipates.
Police don't need a search warrant to go through a vehicle for evidence of a crime. This exception to the warrant requirement exists for two reasons:
- People have less privacy in a car so, in theory, a search is less intrusive
- Cars can be moved quickly, so waiting for a warrant might be too much of an obstacle for law enforcement
4. “Plain View” Searches
Police also don't need a warrant to search for evidence that is in plain view. If the evidence can be found by a police officer from a place they have a right to be, they don't need to get a warrant to do the search.
The extent of a “plain view” search is a hot topic for those done from police helicopters or aerial surveillance.
5. Searches in the “Open Field”
A drastic extension of the “plain view” exception to the warrant requirement that has become an exception in its own right, the “open field” exception allows police to search for evidence of a crime anywhere that the suspect does not have a reasonable expectation of privacy. This can even take them onto a suspect's property.
6. Searches Incident to an Arrest
Police can also search someone they are arresting without getting a warrant, first. This is supposed to allow police to check a suspect for weapons on their person and in their immediate surroundings to keep the officers safe.
Philadelphia Criminal Defense Attorney Joseph D. Lento
The good thing about these warrant exceptions is that it is up to the prosecutor to prove that one of them was in play when police conducted a warrantless search and discovered evidence of a crime.