do

No.  That would be a Fourth Amendment violation.  There are limited exceptions however such as hot pursuit, exigent circumstances.  Unfortunatley state court judges do a very poor job of protecting citizens in this regard and will usually accept any basis given by the police for the illegal search.  Regardless of how incredible the story is and often even when the physical evidence contradicts the officers testimony. They are more concerned with being re-elected/reappointed than protecting the Fourth Amendment.