Texas Rules of Evidence Rule 104. Preliminary Questions

(a) In General. The court must decide any preliminary question about whether a witness is qualified, a privilege exists, or evidence is admissible. In so deciding, the court is not bound by evidence rules, except those on privilege.

(b) Relevance That Depends on a Fact. When the relevance of evidence depends on whether a fact exists, proof must be introduced sufficient to support a finding that the fact does exist. The court may admit the proposed evidence on the condition that the proof be introduced later.

(c) Conducting a Hearing So That the Jury Cannot Hear It. The court must conduct any hearing on a preliminary question so that the jury cannot hear it if:

(1) the hearing involves the admissibility of a confession in a criminal case;

(2) a defendant in a criminal case is a witness and so requests; or

(3) justice so requires.

(d) Cross-Examining a Defendant in a Criminal Case. By testifying outside the jury’s hearing on a preliminary question, a defendant in a criminal case does not become subject to cross-examination on other issues in the case.

(e) Evidence Relevant to Weight and Credibility. This rule does not limit a party’s right to introduce before the jury evidence that is relevant to the weight or credibility of other evidence.