What can the Police Search for when they have Warrant?

The police can only search the place described in a warrant and for only for specific items that the warrant describes.  Furthermore, if the warrant specifies a certain person to be searched, the police can search only that person, unless they have independent probable cause to search other persons who happen to be present at the scene.  Searching beyond the scope of the warrant can cause evidence obtained during that search to be inadmissible (thrown out) at trial.

However, if in the course of a valid search, police officers come across contraband or evidence of a crime that is not listed in the warrant, they can often seize it.