Oregon Revised Statutes Evidence and Witnesses § 40.030

(1) Preliminary questions concerning the qualification of a person to be a witness, the existence of a privilege or the admissibility of evidence shall be determined by the court, subject to the provisions of subsection (2) of this section. In making its determination the court is not bound by the rules of evidence except those with respect to privileges.

(2) When the relevancy of evidence depends upon the fulfillment of a condition of fact, the court shall admit it upon, or subject to, the introduction of evidence sufficient to support a finding of the fulfillment of the condition.

(3) Hearings on the admissibility of confessions shall in all cases be conducted out of the hearing of the jury. Hearings on other preliminary matters shall be so conducted when the interests of justice require or, when an accused is a witness, if the accused so requests.

(4) The accused does not, by testifying upon a preliminary matter, become subject to cross-examination as to other issues in the case.

(5) This section does not limit the right of a party to introduce before the jury evidence relevant to weight or credibility.