I concur in the opinion of the chief justice and in the judgment. That opinion, however, treats only of the case as it is presented upon this appeal, while, in contemplation of the new trial which must necessarily result, it seems to me obligatory upon us to direct the trial court upon the new phases of the question which are certain to arise. Of these, the first is as to the admissibility under any circumstances of this highly injurious testimony tending to show motive. It has been said by this court: "In every criminal case proof of the moving cause is permissible, and oftentimes is valuable." (People v. Durrant,116 Cal. 179, [48 P. 75].) As stated in the opinion of the chief justice, the admissibility or non-admissibility of such offered evidence presents a legal question, to be determined in the first instance by the trial court, and evidence, even though injurious, is not therefore inadmissible if it pertinently and logically tends to show motive for the crime, and thus to solve any doubt which may exist in the case, either as to the identity of the slayer, the degree of the offense, the insanity of the defendant, or to the justification or excusability of his act. It will not, of *Page 351 course, be said that such evidence is admissible merely as the "foundation of an argument." It will not do even to say that such evidence should be admitted when the jury from it might draw an inference of motive. To be admissible it should be of such character as to show a logical, causal connection with the crime, moving the minds of unprejudiced jurors to the belief that it tends to establish the true motive. That evidence of the incestuous relations between defendant and his daughter was admissible in this case to show motive, as well as to throw light upon any doubtful circumstance attending the actual homicide, I am well convinced. Precisely what may be the mental process of one so degenerate it may not be easy to declare; but it is at least understandable from the evidence in the case that while he might not have objected to the marriage of his daughter, since she was to have lived with him, and thus have enabled him to continue the relationship, he might have well become incensed at the dishonorable solicitation of another man who was endeavoring to have sexual intercourse with her. His letters to his daughter show that he regarded himself more as her lover than as her father, and herself more as his mistress than his daughter. And his objection might have been the same objection that has excited many another man to crime when his love affair has been interfered with; or, again, he may have feared that his daughter would have yielded, and that, in the confidences which might follow, his own bestial conduct would be disclosed. That one or another, or both, of these considerations were the moving impulses of his mind seems to me beyond doubt, since no one can credit that having debauched the girl himself he could in any honorable and paternal sense be careful of her chastity or resentful of improper advances made to her by another. And if either of these views, or both, were entertained by the defendant, the fact of his relationship became proper for the jury.
Upon the assumption that the district attorney believed the statements which the girl had made to him, and, so believing, expected her to testify to them under oath, her impeachment was, as pointed out by the chief justice, legitimate evidence. But the situation presented upon a new trial will, in this regard, be entirely different. The district attorney cannot again be taken by surprise, and it would be highly *Page 352 improper, prejudicial, and erroneous to adopt upon a new trial a method which the peculiar circumstances of the first trial alone justified. It is never permissible for an attorney to offer a witness in the expectation, or with the knowledge, that that witness will testify to a given fact, merely for the purpose of establishing the contrary by purely hearsay testimony. This would be subversive of the fundamental principles of evidence. Therefore, I think it should be pointed out that, while legitimate evidence of the incestuous relationship is admissible upon a new trial, such evidence cannot be presented to the jury by the method which the circumstances of the first trial alone made permissible.
Lorigan, J., concurred.