The 4th Amendment protects you from “unreasonable” searches and seizures by the police. A search may be more reasonable if the police get a search warrant signed by a neutral third party, often a judge. However, every search does not require a warrant. Understanding when a warrant may or may not be necessary can help you understand your rights.

Do you have an expectation of privacy?

Generally speaking, if you have a reasonable expectation of privacy, the police would likely need a warrant. For example, most people consider their homes to be private. Thus, a warrant is often necessary to search your living space. On the other hand, you would not have a reasonable expectation of privacy in your front yard. If you had a robust garden of marijuana plants growing out front, the police would probably not need a warrant to make an arrest or gather evidence.

Other situations where a warrant may not be necessary

As shown in the above example, police do not need a warrant if there is evidence of illegal activity in plain view. Other situations where police may not need a search warrant include:

  • When you give the police consent to search your home or vehicle
  • Searches carried out in government buildings or in schools
  • If the police have probable cause to suspect criminal activity during a traffic stop

Often, warrant requirements depend largely on your location.

What happens if the police find evidence during an illegal search?

The legal concept known as the “exclusionary rule” means that evidence obtained illegally by the police cannot be used to discover additional evidence of criminal activity. For example, the police illegally search a home and find bundles of marijuana. They also find the address of a grow house. The police then go to the address of the grow house and based on the evidence found at the grow house tack on additional criminal charges.

The bundles of marijuana found in the house cannot be used as evidence because the search was illegal. The discovery of the grow house also cannot be used as evidence because the police only discovered the address as part of the illegal search.

Although evidence gathered during an illegal search is inadmissible, this doesn’t mean you’re in the clear. There may be other, legal pieces of evidence that the prosecution can use to build their case against you. You should always discuss your options with a trusted legal professional.