Probable cause along with exigent circumstances may justify a search or entry without a warrant. 2 This is also known as the "emergency doctrine.Understand the 4th Amendment and when consent to search your house is legally valid. Learn who can give consent in Texas. A. Any search warrant that appears to be in proper form is presumed to be valid. Any warrant which does not appear to be in. Politely, but firmly "No sir, you may not enter my home in an official capacity unless you have a warrant. Applicants must not have any of the disqualifying items listed below on their record: a.