¶1Defendant appeals a conviction of second-degree murder and first-degree assault with a deadly weapon. We reverse and remand the case for a new trial.
¶2On an early August morning the defendant while at the home of a friend, Mrs. Hooper, wounded one man and fatally shot another who allegedly had molested Mrs. Hooper’s 7-year-old daughter. Immediately after the shooting, Mrs. Hooper called the police by way of the Spokane Police Crime Check emergency telephone number. During the conversation Mrs. Hooper stated: “Please come to 2903 E. Gordon, there is a guy broke in and my girlfriend shot him.” Subsequently the defendant took the telephone and spoke to the police operator stating that she had shot two people and “we warned you—we told you guys.” Without the knowledge or consent of Mrs. Hooper or the defendant the telephone conversation was recorded. The resolution of the dispositive issue, whether the trial court erred in admitting into evidence the tape recording, rests on an interpretation of three recently enacted statutes.
¶3RCW 9.73.030 provides that it is unlawful for a municipality to record “private” communications between *117the individuals without the consent of all participants to the conversation. Evidence obtained in violation of this statute is not admissible in a criminal proceeding under RCW 9.73.050. An exception to these general rules is found in RCW 9.73.090.
unnecessarily fail to give full effect to the legislative purpose to protect the freedom of people to hold conversations intended only for the ears of the participants.
¶4The telephone call was a “private communication” as that term is used in RCW 9.73.030(1). This conclusion presents the following issue: Can a communication which is lawfully recorded under RCW 9.73.090 be admitted into *118evidence in a criminal prosecution of a participant to the conversation?
¶5The evidentiary prohibition contained in RCW 9.73.050, while excluding evidence obtained in violation of RCW 9.73.030, is silent as to the admissibility of a recording made under the authority of RCW 9.73.090(1). Thus, we must look to the legislative intent underlying RCW 9.73.090(1).
On the other hand a person phoning the police department probably is not being injured particularly by having his call recorded. If he is talking with a public official, he probably expects it to be public information. It is not public information, of course, because these are held confidential . . .
. . . I do not think that they should have these things recorded when the people do not know they are being recorded. The point is that they are trying to make sure that they get the right address when they have a call to a robbery or they get the right address and so forth when a call comes in that the house is on fire.
¶6Senate Journal, Forty-First Legislature, 2d Ex. Sess. (1970) at 205. Thus to admit a recording pursuant to RCW 9.73.090 into evidence in this case emasculates the prohibition of RCW 9.73.050 and makes the limited purpose of the recording a sham.
¶7The plaintiff urges, in support of the trial court’s ruling that since the defendant pleaded not guilty by reason of insanity it was proper to introduce any and all evidence of her conduct relevant to her state of mind at or near the time of the shooting.
¶8Although patently dissimilar, the prohibition found in RCW 9.73.050 is analogous in its operation to the physician-patient privilege. As observed in C. McCormick, Law of Evidence § 72, at 152 (2d ed. E. Cleary 1972) the sole purpose of such exclusionary statutes is not to aid the courts in determining the truth but to protect other interests and relationships deemed of greater importance than the truth.
¶9Just as commencement of a personal injury action does not waive the plaintiff’s right to assert the physician-patient privilege
¶10While evidence of the content of the conversation be*120tween the defendant and the crime check operator is arguably admissible through the operator,
¶11The remaining question is whether the error in admitting the tape constituted reversible error. After submission of the case, the jury deliberated on May 12, 1973, without access to the tape even though they requested to hear it again. The trial court refused this request until the following day at about 9:30 a.m. when the court allowed the jury to play the tape recording one time. Approximately 45 minutes later the jury reached a verdict. Prejudicial error is one which affects or presumptively affects the final results of the trial.
¶12Finally, error is assigned to the trial court’s exclusion of expert testimony relating to the defendant’s Indian culture. Inasmuch as this issue may arise on retrial, we address ourselves to this issue. Defendant’s counsel proposed calling an expert witness on Indian culture to testify: Indians are very family oriented; they maintain a strong feeling of respect for their elders; and unnatural sex acts are not accepted by Indian culture. Specifically, defendant’s expert witness would have testified that an Indian, confronted by an older person attempting to perform an unnatural sex act on a young child, would undergo a more traumatic emotional experience than would a member of the Anglo-Saxon culture because of the highly respected position an older person possesses in the Indian culture.
¶13It is generally within the trial court’s discretion to *121exclude or admit expert opinion.
¶14Judgment of the superior court is reversed and the case is remanded for a new trial consistent with this opinion.
¶15 RCW 9.73.090 provides in part:
“The provisions of RCW 9.73.030 through 9.73.080 shall not apply to police and fire personnel in the following instances:
“(1) Recording incoming telephone calls to police and fire stations for the purpose and only for the purpose of verifying the accuracy of reception of emergency calls.” (Italics ours.)
¶16 The phrase “private communication” is not found in the language of the Federal Communications Act, 47 U.S.C. § 605.
¶17 In re Estates of Donnelley, 81 Wn.2d 430, 436, 502 P.2d 1163 (1972).
¶18 State v. Huson, 73 Wn.2d 660, 440 P.2d 192, cert. denied, 393 U.S. 1096, 21 L. Ed. 2d 787, 89 S. Ct. 886 (1968); 2 J. Wigmore, Law of Evidence § 228, at 9 (3d ed. 1940). The rationale for this contention *119may be found in Green, Proof of Mental Incompetency and the Unexpressed Major Premise, 53 Yale L.J. 271, 276 (1944). The author notes that mental disorder manifests itself through behavior or individuals, i.e., their speech, conduct, activities. The tape recording is very persuasive evidence in determining the question of the defendant’s mental irresponsibility. Things which she spoke about, the manner in which she spoke them and the sound of her voice would be an invaluable aid for a jury faced with the problems of determining the defendant’s mental state.
¶19 See Olsen v. Nebraska, 313 U.S. 236, 246, 85 L. Ed. 1305, 1306, 61 S. Ct. 862 (1941).
¶20 See Petersen v. Department of Labor & Indus., 40 Wn.2d 635, 637, 245 P.2d 1161 (1952). The observation of Aristotle is apropos: “Even when laws have been written down, they ought not always to remain unaltered.”
¶21 Bond v. Independent Order of Forresters, 69 Wn.2d 879, 421 P.2d 351, 25 A.L.R.3d 1394 (1966).
¶22 See State v. Miller, 177 Wash. 442, 32 P.2d 535 (1934).
¶23 See State v. Grant, 9 Wn. App. 260, 267, 511 P.2d 1013 (1973).
¶24 State v. Mack, 80 Wn.2d 19, 21, 490 P.2d 1303 (1971).
¶25 State v. Martin, 73 Wn.2d 616, 440 P.2d 429 (1968).
¶26 The decedent was not attempting to commit an unnatural sex act on a young child at the time he was shot by the defendant.
¶27 Swartley v. Seattle School Dist. 1, 70 Wn.2d 17, 21, 421 P.2d 1009 (1966).
¶28 Hill v. C & E Constr. Co., 59 Wn.2d 743, 746, 370 P.2d 255 (1962).