Seizing Evidence from a Home: Police Procedure
The U.S. Constitution and all state constitutions set rules on when and how the police can seize evidence. General constitutional principles are usually defined in each state's rules of criminal procedure. Usually a warrant is required to seize evidence. However, the Supreme Court has identified consent as an exception to this rule.
Consent and the Ability to Seize Evidence
If you consent to the police entering your home to conduct a search and you allow them to seize evidence, this will meet the warrant exception. If you only consent to the entry, but not the seizure of the evidence, then another warrant exception comes into play. This is called the plain view exception.
If the police are in your home lawfully, with your consent, and they see items in plain view that represent evidence of a crime, and if these items appear in an area where you have allowed the police to search, then the police can seize the evidence as another exception to the warrant requirement. The police are not required to ignore what they immediately recognize as evidence. But this does not mean that they can come in and take everything in your home. The police must demonstrate how each seized item relates to a crime.
Withdrawing Your Consent
If you allow the police into your home, you can withdraw your consent at any time while they are there. If you do so, the police are required to leave unless they have already seen evidence of a crime. If they have already seen or begun to seize evidence, the police do not have to leave upon your withdrawal of consent. One officer can detain you while the other obtains a search warrant for the rest of your home based on what they saw in plain view. After the warrant is signed and issued, the police are able to seize evidence they find.