Texas Penal Code - PENAL § 38.03. Resisting Arrest, Search, or Transportation

(a) A person commits an offense if he intentionally prevents or obstructs a person he knows is a peace officer or a person acting in a peace officer's presence and at his direction from effecting an arrest, search, or transportation of the actor or another by using force against the peace officer or another.

(b) It is no defense to prosecution under this section that the arrest or search was unlawful.

(c) Except as provided in Subsection (d), an offense under this section is a Class A misdemeanor.

(d) An offense under this section is a felony of the third degree if the actor uses a deadly weapon to resist the arrest or search.