Tex. Code of Criminal Procedure § 18.0215

(a) A peace officer may not search a person's cellular telephone or other wireless communications device, pursuant to a lawful arrest of the person without obtaining a warrant under this article. A wireless communications device does not include a skimmer as defined by Section 607.001, Business & Commerce Code, or a device manufactured for the purpose of illicitly obtaining payment card information or identifying information.

(b) A warrant under this article may be issued only by a judge, including a judge of a statutory county court, in the same judicial district as the site of:

(1) the law enforcement agency that employs the peace officer, if the cellular telephone or other wireless communications device is in the officer's possession; or

(2) the likely location of the telephone or device.

(c) A judge may issue a warrant under this article only on the application of a peace officer. An application must be written and signed and sworn to or affirmed before the judge. The application must:

(1) state the name, department, agency, and address of the applicant;

(2) identify the cellular telephone or other wireless communications device to be searched;

(3) state the name of the owner or possessor of the telephone or device to be searched;

(4) state the judicial district in which:

(A) the law enforcement agency that employs the peace officer is located, if the telephone or device is in the officer's possession; or

(B) the telephone or device is likely to be located; and

(5) state the facts and circumstances that provide the applicant with probable cause to believe that:

(A) criminal activity has been, is, or will be committed; and

(B) searching the telephone or device is likely to produce evidence in the investigation of the criminal activity described in Paragraph (A).

(d) Notwithstanding any other law, a peace officer may search a cellular telephone or other wireless communications device without a warrant if:

(1) the owner or possessor of the telephone or device consents to the search;

(2) the telephone or device is reported stolen by the owner or possessor; or

(3) the officer reasonably believes that:

(A) the telephone or device is in the possession of a fugitive from justice for whom an arrest warrant has been issued for committing a felony offense; or

(B) there exists an immediate life-threatening situation, as defined by Article 18A.201.

(e) A peace officer must apply for a warrant to search a cellular telephone or other wireless communications device as soon as practicable after a search is conducted under Subsection (d)(3)(A) or (B). If the judge finds that the applicable situation under Subsection (d)(3)(A) or (B) did not occur and declines to issue the warrant, any evidence obtained is not admissible in a criminal action.