The Fourth Amendment to the?US Constitution protects you against unreasonable searches and seizures. But how, exactly? Under what’s commonly called the Fourth Amendment’s “warrant requirement ,” law enforcement agents need a warrant to search a person or place and seize evidence of a crime or illegal items. There are some exceptions to the warrant requirement, but, generally, a search conducted by law enforcement agents without a warrant, or in violation of a warrant, is unreasonable. And, under the exclusionary rule, any evidence that’s obtained in violation of the Fourth Amendment – that is, through an illegal or unreasonable search – can’t be used against you at trial.

Search Warrant Basics

A search warrant is a court order that authorizes law enforcement agents to search a particular place, like your home or office, and seize or take particular things, like evidence of a crime. Law enforcement agents have to ask a magistrate or judge for a search warrant. They do this by giving him a sworn statement, called an “affidavit,” that explains why they think there’s evidence of a crime in the place they want to search. If, based upon the affidavit, the magistrate or judge thinks that there’s probable cause to search for and seize property, he’ll give the agents a warrant. Generally, there’s probable cause to search when all the facts and circumstances given in the affidavit convince the magistrate or judge that there’s a fair probability that contraband or evidence of a crime will be found in the place that the agents want to search.

In addition, agents have to tell the magistrate or judge exactly where they want to search and what they want to seize. This is called the particularity requirement. Generally, once a warrant is issued, law enforcement agents can search only the area or place specified in the warrant and they can seize only the items specified in the warrant.

Exclusionary Rule in Action

The exclusionary rule is not in the US Constitution. Rather, the Supreme Court of the United States created the rule so that the Fourth Amendment’s protection against unreasonable searches and seizures can be enforced. That is, the rule is designed to help make sure that law enforcement agents conduct searches and seizures properly.

How does it do this? If the police make an unlawful search and seizure and you’re later charged with a crime, you can ask the court to exclude or “suppress” the evidence that was seized improperly. If the court agrees and finds that the police acted improperly, any evidence that they seized can’t be used against you in court. The idea is simple: If law enforcement agents know beforehand that evidence obtained in violation of the Fourth Amendment can’t be used against you in court, they’ll work to make sure that they don’t violate the Fourth Amendment.

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A search and seizure can be unlawful for any number reasons, but some good examples include:

  • When agents or the police search an area not authorized by the search warrant and with no other legal justification. For example, if the warrant allows them to search your back yard, they generally can’t enter and search your home
  • When a search and seizure is made without a warrant and without legal justification or “probable cause.” For example, if you’re stopped by an officer for speeding, the officer generally can’t search the trunk of your car unless he has some reasonable belief or probable cause to believe that you’ve committed a crime (other than speeding) or that the trunk contains contraband
  • When the police search an area that can’t contain the item or items listed in the search warrant. For instance, if the search warrant allows the police to search your property for a stolen lawn mower, they can’t rummage through the desk in your den or the drawers of the dresser in your bedroom

Exceptions to the Exclusionary Rule

In general, there are three exceptions that allow evidence that was obtained through an illegal search and seizure to be used against you:

  • Inevitable discovery doctrine. Under this exception, evidence can be used against you if, before the illegal search or seizure, the facts known and the agents’ investigative method would’ve almost certainly or “inevitably” led to the discovery of the same evidence. For example, say that police officers interrogate a suspect about the whereabouts of the body of a victim he’s suspected of killing, and he tells them where to look. At the same time, other officers are searching in an area they think the body is located, and they find it. It’s in the same place described by the suspect. Even if the officers’ interrogation violated the suspect’s constitutional rights, the evidence of the body may still be used against him because it was very likely that the police inevitably would’ve found the body anyway
  • Independent source doctrine. Here, the Fourth Amendment doesn’t require evidence to be suppressed that was first discovered during an illegal entry and search if that evidence is also discovered during a later search under a valid warrant that is completely independent of first illegal entry. For example, after an investigation and surveillance, police officers arrest a suspect outside his home for drug-related crimes. They then enter his home without a warrant and without permission. They see drug paraphernalia in plain view. Some officers stay in the home while other officers get a warrant. Several hours later, the home is searched with a valid warrant and a large amount of illegal drugs are found. Even though the first entry was illegal under the Fourth Amendment, the evidence seized in the second search may still be used in court because the warrant was based on information that was independent of the first search. That is, the warrant was based on the officers’ investigation and surveillance, not the illegal first search
  • Good faith doctrine. Under this exception, evidence that’s illegally seized may be used against you if law enforcement agents had a good faith belief that they were acting lawfully when the evidence was seized. For example, after an investigation of illegal drug activities, a police officer applies for and gets a search warrant from a judge, searches the suspect’s home, and finds a large amount of illegal drugs. Later, a court finds that the warrant was invalid because there wasn’t enough evidence against the suspect to justify the search. However, because the officer had a good faith belief that the warrant was valid, the evidence found in t suspect’s home may still be used against him in court

Questions for Your Attorney

  • What exactly do I need to do to have evidence suppressed if I think the police searched my home illegally?
  • I represented myself when I was charged with illegal gambling, and I was able to get the evidence suppressed. I thought the prosecution would drop the case, but it hasn’t. Why not?
  • My boyfriend’s house was searched and the police took his computer. He has some files on his computer that belong to me. I haven’t been charged with a crime. Can I challenge the police officers’ search and seizure and get my computer files back?