MELVIN, J.

Defendant was convicted of the crime of burglary of the first degree. He was sentenced to imprisonment for the term of ten years.

It was the theory of the prosecution that the defendant, on or about July 21, 1912, entered the office of the district attorney of Glenn County with intent to commit larceny and that he stole and took away from said office certain letters, a hotel register, and a page which had been torn from the register of another hotel. These articles had been used before the grand jury during the proceedings which led to the indictment of one Otto Klemmer on the charge of contributing to the dependency of a minor. Defendant appeals from the judgment and from the order denying his motion for a new trial, urging as reasons for reversal: 1. That there was no proof of the corpus delicti aside from the confessions of the defendant; 2. That the court committed error in certain rulings on the admissibility of testimony; and, 3. That there was no evidence showing the commission of the alleged offense in the night-time, and hence no proof justifying a verdict of burglary of the first degree.

The district attorney testified that after the indictment of Otto Klemmer he took the exhibits with him to his office. The letters were placed in his files and the hotel register containing folded up within it, the leaf from the other hotel register was put in a drawer in his desk. He saw the exhibits at various times until about two weeks before he discovered that they were missing. On or about July 21, 1912, he had occasion to examine the exhibits and then found that they were not in his office. He and his stenographer made careful search and in the course of the investigation he found that the screen to the window of the room in which the papers had been filed, was cut. About three feet below the window, outside of the building, was the surface or top of a cellar door. The district attorney thus described the condition of the screen: "There was a steel post that went through the screen into the hole in the wall. At this point here it was, which was about nine inches about, above the lower east corner of the window and one that went through the opposite side, the west side of the window, and also another that went through on the east side of the screen here, being the same kind of screen as this is in size, but old. (Referring to screen in courthouse window back of witness chair.) The steel post that went through this part of the window had a mark on it, corrugated marks, running lengthwise the same way as the post did, of bright, new, freshly put on there marks, and this side of the window had been forcibly torn out, splitting the wood. The screen had also been torn loose from the jamb of the window on this side of the top." Witness also stated that he had seen tracks of a man's shoes outside of the building and passing under one of the windows of his office. These tracks were in the freshly worked ground between the building and the beaten path. He had observed these tracks a few days before he missed the exhibits from his office, his attention having been directed thereto by the janitor. This testimony, which was corroborated by other witnesses, who saw the broken screen and the tracks under the window, related all of the facts upon which the prosecution sought to establish the corpus delicti aside from the alleged confession of the defendant. On the witness-stand the defendant denied that he had entered the office of the district attorney or that he had made any confession. Witness Noble related two alleged confessions and witness Wieland testified that he overheard one of them. Noble stated that between the first and the second conversations with the defendant he went to the district attorney and told that officer that he could "produce the man that committed the crime or said he had," but did not mention any name. After the second conversation with defendant, according to Noble's testimony, he told the district attorney the name of the man who had made the confessions. The first confession, as related by Noble, was as follows: "Mr. Vertrees told me that he entered the office of the district attorney Purkitt, and secured some papers, took some papers that was evidence pertaining to the Otto Klemmer case; that he entered through the window and he got the papers; some were on file and some were in the north drawer of the desk, and he left the office in company with Mr. Lenus Klemmer; went to the Sacramento River and burned the papers." The conversation, he said occurred in the yard of the premises where he and Vertrees lived. The second conversation, according to Noble, took place near the back door of the house. To quote Noble's own words: "I asked him how he got in the office and got the papers without being detected without a light in the small hours of the morning, and he said he entered the window and got the papers, some of them were on file and some were in the north end of the drawer and I believe he said he had a flashlight and I am not positive about that. I asked him about the light and whether he said he turned on the light or had a flashlight, I am not positive, but he told me then that he got them and where they were and how he left with him." Wieland said that he overheard a conversation between Vertrees and Noble as they stood near the back door of the house. Witness was in a shed connected with the house, and was concealed from the view of Vertrees. Regarding this conversation Wieland said: "I can give the substance of it, not in any exact words or anything, but Vertrees told Noble that he had come to the court house with Lenus Klemmer and entered the window of the district attorney's office and took the evidence in the Otto Klemmer case while Lenus Klemmer stood guard with the machine. . . . They took the papers in the machine and took them out the Jacinto Road and burned them." The janitor and the stenographer connected with the district attorney's office testified that neither of them had taken away the exhibits and that neither of them knew anything about the disappearance of those articles.

It is the settled law that no conviction may be had upon the extra-judicial confession of a defendant unless such confession be corroborated by proof aliunde of the corpus delicti, and while slight proof of the corpus delicti has in many cases been properly held a sufficient basis for the admission of such confessions, it is nevertheless true that the confessions and admissions of the defendant cannot be used to establish any necessary element for the commission of the crime. (People v. Simonsen, 107 Cal. 346, [40 P. 440]; People v. Jones, 123 Cal. 68, [55 P. 698]; People v. Tapia, 131 Cal. 651, [ 63 P. 1001]; People v. Frank, 2 Cal.App. 285, [ 83 P. 578]; People v. Frey, 165 Cal. 144, [ 131 P. 127].) Applying these rules with all liberality we cannot say that the corpus delicti was proven without the alleged confession of Vertrees. The district attorney's office is a public one and the fact that papers disappeared from it would not prove that burglary had been committed. The circumstance that a window screen had been broken did not establish either an unlawful entry or the stealing of the exhibits by the person making such entry. It was not shown that the papers and the hotel register were in the office at the time the window screen was broken or at the time when the tracks appeared on the soft earth outside of the office. Undoubtedly the corpus delicti may be proven by circumstantial evidence, but the circumstances related by the district attorney and the other witnesses who corroborate his statements utterly fail to establish the crime of burglary. The two elements of corpus delicti are: "1. Certain facts forming its basis; and, 2. The existence of criminal agency as the cause of them." (People v. Jones, 123 Cal. 68, [55 P. 698].) Both of these elements were lacking until they were supplied by Noble and Wieland, who repeated alleged conversations with Vertrees. Without the details given in their testimony no one could positively say that burglary had been committed by some one entering the office of the district attorney with intent to commit larceny. While the facts related by the district attorney would properly arouse his suspicions, they would not amount to circumstantial proof of the crime charged. It has been held in this state that although all of the elements of the crime charged must appear in the proof of the corpus delicti, it is not necessary that the evidence of the criminal act should be of the conclusive character required for conviction before the confession may be admitted in evidence. (People v. Spencer, 16 Cal.App. 759, [ 117 P. 1039]; People v. Rowland, 12 Cal.App. 10, [ 106 P. 428].) But no authority has been cited which justifies the use of the confession itself to prove one or more of the necessary elements in the commission of the crime that would be wholly lacking without such confession.

We see no reason for extending a rule based on reason and experience and intended to protect a defendant from the possibility of fabricated testimony out of which might be wrongfully established both the crime and its perpetrator. Confessions themselves as presented in court have been described by leading text-writers as the sort of testimony calculated to arouse and stimulate suspicions. (Wharton on Criminal Evidence (10th ed.), sec. 635; Wigmore on Evidence, sec. 866.) We should therefore preserve the safeguards surrounding their lawful introduction. It follows that the judgment must be reversed for the reasons above stated.

The defendant testified in his own behalf. On cross-examination he was asked if he had ever been convicted of a felony. He replied in the affirmative, saying that the crime of which he had been convicted was an attempt at burglary. He denied that he had ever been convicted of any other felony and the district attorney was permitted, over the objection of defendant's counsel, to show by the record of a trial in which Vertrees had appeared as a witness that he had admitted a previous conviction of the crime of manslaughter, committed in the state of Oregon. The prosecution seeks to justify this course under section 2052 of the Code of Civil Procedure, while defendant's counsel insist that the fact of prior conviction may only be shown by the admission of the witness or the production of the record (Code Civ. Proc., sec. 2051), and that admissions made by him at other times and places touching the matter of his former conviction may not be shown in lieu of the written record of his conviction and imprisonment. As the district attorney will have ample time before the next trial to produce the record of conviction, if one exists, we need not discuss this question. If the record is not in existence of course the prosecuting officer will not ask the witness anything about conviction of a felony in Oregon.

Against the objections of defendant's counsel the indictment against Otto Klemmer was introduced in evidence. Defendant was not injured by the introduction of this piece of evidence as it was already in proof that such an indictment had been returned and that the missing exhibits had been used as evidence before the grand jury that returned it. It was improper for the prosecuting officer to ask Otto Klemmer on direct examination when he was called as a witness for the people if he (witness) were the same person who had been tried under the name of Otto Klemmer on certain dates and if he were the person who had been indicted at a certain time. Such questions could only have been propounded for the purpose of impeachment and even granting that the witness may have been hostile to the prosecution it was not within the rights of the district attorney to call him merely for the purpose of throwing discredit upon him. When the questions were asked the witness had uttered no word of testimony showing any bias or prejudice toward the commonwealth's case.

The witnesses Noble and Wieland testified that during a talk with the defendant the latter reached in his pocket, pulled out a paper and said, "Gee, here is something I thought I had lost or spent." The paper, witnesses said, was a check on the Glenn County Bank, apparently drawn by Otto Klemmer for two hundred and seventy-five dollars, and made payable to Jesse O. Vertrees. The time of the conversation and the exhibiting of the check was fixed as being before Vertrees made confession of the burglary. There was no further showing with reference to this check, except that Otto Klemmer was permitted to prove by his checkbook and his canceled checks that no issuance of any check to Vertrees appeared therefrom. The prosecution made no connection between this check and the crime for which Vertrees was on trial. The learned attorney-general defends the introduction of this testimony on the ground that it tends to exhibit the motive of the defendant for the commission of the alleged burglary. As there was no showing and no attempt to prove that the check was given for any particular purpose and as its alleged existence was attributed to a time long after the disappearance of the papers we fail to see its relevancy as showing motive or for any other purpose.

Lenus Klemmer was jointly indicted with the defendant Vertrees. He was mentioned in the testimony of the witnesses Noble and Wieland as the person inculpated by Vertrees's confession in the crime of burglariously entering the office of the district attorney. He took the stand and testified that he had not participated in nor had he been cognizant of any burglary. On cross-examination he admitted that he was interested in the case, being charged jointly with Vertrees. Later, in the cross-examination of this witness the court permitted the district attorney to ask him certain questions about a forged check not, as the court said, for the purpose of proving that the defendant Vertrees had committed forgery, but to show the bias of the witness. The prosecution on cross-examination developed the fact that Lenus Klemmer had become possessed of a certain paper purporting to be a check drawn by Otto Klemmer but really, as Vertrees confessed, written by him. This check was for one hundred dollars. The grand jury was investigating the matter of that forgery — a fact, as witness admitted, which was known to him. He was then asked the following question and after the overruling of an objection gave the appended answer. "I will ask you then, Mr. Klemmer, if you at that time advised your son, Otto, concerning the prosecution of Mr. Vertrees about that check, referring to the matter then before the grand jury? . . . A. I told him it was his business and not mine, he could do as he pleased." Witness also stated that he knew of an arrangement whereby Vertrees borrowed the money to make the check good and that he agreed to pay over a small amount of this indebtedness each week to the creditor out of the wages of Vertrees who was employed by the witness. The prosecution insists that the cross-examination of Lenus Klemmer comes within the exception to the general rule that proof of other offenses is not permissible in the trial of a person charged with crime. But this cross-examination does not come within the doctrine which admits evidence of other crimes to prove the motive of the defendant. Such cases as People v. O'Bryan, 165 Cal. 58, [ 130 P. 1042]; People v. Walters, 98 Cal. 141, [32 P. 864], and others, cited in that behalf have no application to the facts of this case. The general rule is that the prosecution is not only forbidden to prove another crime but may not introduce evidence designed merely to degrade and prejudice the defendant before the jury. (People v. Glass, 158 Cal. 655, [ 112 P. 281].) Nor may a cross-examiner do indirectly that which the law prohibits him from doing directly. (People v. Vidal, 121 Cal. 222, [53 P. 558].) Having elicited the fact that Lenus Klemmer was interested in the acquittal of Vertrees he was not then privileged to go further and under the guise of developing bias elicit the story of a transaction, the details of which must have been injurious to the defendant, but could have no connection with the commission of the burglary charged in the indictment. In Jones's Commentaries on Evidence (vol. 5, sec. 829, p. 151), the rule is thus stated: "The rule has several times been declared in judicial decisions that, where the cross-examiner ascertains from the admission of the witness that he is prejudiced against or entertains a feeling of hostility toward the adverse party, the inquiry cannot be pressed further to show the cause or ground of such hostility, or the details of the facts showing bias." People v. Goldenson, 76 Cal. 328, (349), [19 P. 161], is cited by the learned author in support of the text. In People v. Breen, 130 Cal. 78, [ 62 P. 408], a witness for the prosecution was president of the company that employed a detective to ascertain the origin of the fire which, according to the indictment, was set by the defendant. Defendant's counsel asked witness how much had been paid to the detective for his services and this court approved a ruling sustaining an objection to the question. Applying this principle to the case at bar we must hold that after the prosecution had obtained from the witness an admission of his interest in the acquittal of the defendant, he could not be interrogated additionally to the extent of eliciting facts tending to prove a crime committed by Vertrees but having no possible connection with the offense of burglary for which the latter was on trial.

The only testimony of burglary of the first degree is found in the statement of Noble which is quoted herein. The time of entering a building is one of the essential elements of the crime of burglary of the first degree and that constituent of the offense may not be proved by the confession of the defendant alone.

Appellant complains of the giving of this instruction: "If any witness examined before you has willfully sworn falsely in this case to any material matter, it is your duty to distrust his entire evidence." This form of the instruction was disapproved in People v. Delucchi, 17 Cal.App. 103, [ 118 P. 935], and if this case shall be tried again we would suggest an adherence to the form which has been approved.

The judgment and order are reversed.

Lorigan, J., concurred.