The Fourth Amendment to the United States Constitution states:
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
— US Const., amend. 4 (1791)
Article 1, § 9 of the Texas Constitution states:
The people shall be secure in their persons, houses, papers, and possessions, from all unreasonable searches or seizures, and no warrant to search any place, or to seize any person or thing, shall issue without describing them as near as may be, nor without probable cause, supported by oath or affirmation.
— Tex. Const., art. 1, § 9
The purpose of the Fourth Amendment and Article 1, § 9 is to safeguard the privacy and security of individuals against arbitrary invasions by government officials. However, not all searches and seizures are prohibited, only those that are unreasonable. The reasonableness of a search or seizure is determined by a review of the totality of the circumstances of each particular case and by balancing the the public interest served against an individual’s right to be free from arbitrary intrusions at the discretion of law enforcement officers.
The Fourth Amendment requirement of reasonableness consists of three parts: (1) the search or seizure must be justified by probable cause; (2) the search or seizure must be conducted pursuant to a warrant or to a recognized exception to the warrant requirement; and (3) the manner of conducting the search or seizure must be reasonable.