Police will often ask a person for permission to search their home, car, or person. It is almost never wise to give such permission, for a variety of reasons.
Search Warrant
What to Do After Your Home is Raided in a Criminal Investigation (Search Warrant Execution)
When a person is suspected of a crime, the police will often raid the person’s home in search of evidence. More formally, this is referred to as the execution of a search warrant.