What are the police allowed to do after they obtain a search warrant?

Once the police have a search warrant, they are entitled to enter the designated property to search for the items listed on the warrant. Legally, the search is supposed to be confined to the specific areas described in the warrant. For example, if the search warrant includes only the living room, the search should not extend into the kitchen, bathroom or bedroom. But there are exceptions to this limitation which are frequently used to justify broader searches. For example, the police may search beyond the terms of the warrant in order to:

• ensure their safety and the safety of others
• prevent the destruction of evidence
• discover more about possible evidence or contraband that is in plain view elsewhere on the property, or
• hunt for evidence or contraband that, as a result of their initial search, they believe exists in another location on the property.

For instance, although a warrant might be issued for the search of a house, the sound of a shotgun being loaded in the backyard would justify expanding the search to the yard in order to protect the officers; similarly, a search limited to the ground floor might legitimately expand to the upstairs if the police, searching for illegal drugs, hear toilets being flushed above. And the police can always seize evidence or illegal items if they are in plain view or are discovered while the officers are searching for the items listed in the warrant.

Do the police always need a warrant to conduct a search?

No. In many situations, police may legally conduct a search without first obtaining a warrant.

• Consent searches. If the police ask your permission to search your home, purse, briefcase or other property, and you agree, the search is considered consensual, and they don't need a warrant. The police typically obtain a person's consent by threatening to detain her while they obtain the warrant.
• Searches that accompany an arrest. When a person is placed under arrest, the police may search the person and the immediate surroundings for weapons that might be used to harm the officer. If the person is taken to jail, the police may search to make sure that weapons or contraband are not brought into the jail. (This is called an inventory search.) Inventory searches also frequently involve a search of the arrested person's car (if it is being held by the police) and personal effects on the theory that the police need a precise record of the person's property to avoid claims of theft.
• Searches necessary to protect the safety of the public. The police don't need a warrant if they have a reasonable fear that their safety, or that of the public, is in imminent danger. For example, an officer who suspected a bomb-making operation while walking his beat might be justified in entering immediately and seizing the ingredients. And in the famous O.J. Simpson case, the police justified their entry onto O.J. Simpson's property on the grounds that they feared for the safety of other family members.
• Searches necessary to prevent the imminent destruction of evidence. A police officer does not need to obtain a warrant if she has observed illegal items (such as weapons or contraband) and believes that the items will disappear unless the officer takes prompt action. This exception arises most frequently when the police spot contraband or weapons in a car. Because cars are moved so frequently, the officer is justified in searching the entire vehicle, including the trunk, without obtaining a warrant. On the other hand, if the police learn about a marijuana-growing operation from a neighbor, they usually would need a warrant, as it is unlikely that the growing plants and other evidence of the operation will disappear quickly enough to justify a warrantless search.
• "Hot pursuit" searches. Police may enter private dwellings to search for criminals who are fleeing the scene of a crime.

Can my roommate-or my landlord-give the police permission to search my apartment?

The police may search your apartment if the person in charge of the premises gives permission. If you and your roommate share common areas (such as the kitchen and living room), your roommate can authorize a search of those areas. But your roommate cannot give permission to search your separate bedroom.

Similarly, your landlord cannot give permission to search your apartment. Although the landlord owns the property, your monthly check guarantees your privacy at home. This is true even if you are behind in your rent or your landlord has sued to evict you. Until the landlord has a court order that permits him to enter and retake the premises, he cannot enter without your permission. (But keep in mind that many states allow a landlord to enter for inspections, which usually require advance notice of a day or two.) If the police can point to circumstances that would justify immediate entry, however -- such as the sound of a ferocious fight or the smell of burning marijuana -- they may enter without permission from anyone.