¶1Concurring Opinion by
¶2The majority concludes that the failure to raise an insanity defense at an unrelated trial 18 months earlier, for a separate offense occurring 33 months earlier, is evidence admissible to rebut appellant’s defense of insanity raised in the instant case. I cannot accept this contention.
¶3“Any analysis of the admissibility of a particular type of evidence must start with a threshold inquiry as to its relevance and probative value.” Commonwealth v. McCusker, 448 Pa. 382, 391, 292 A.2d 286, 289 (1972). Evidence to be relevant must tend to prove or disprove the existence of a particular material fact. “[T]he most acceptable test of relevancy is the question, does the evidence offered render the desired inference more probable than it would be without the evidence?” McCormick, Handbook of the Law of Evidence, 437 (2d ed. 1972) (emphasis original). See Mutual Life Ins. Co. v. Hillmon, 145 U.S. 285 (1892) ; People v. Warner, 270 Cal. App. 2d 900, 76 Cal. Rptr. 160 (1969). Relevant evidence must have probative value and in some degree advance the inquiry. Commonwealth v. Jones, 459 Pa. 62, 327 A.2d 10 (1974). Evidence will be admissible if it “tends even somewhat remotely to show that a fact in controversy *137did or did not exist.” 1 Wharton’s Criminal Evidence 287 (13th ed. 1972). In my opinion the rebuttal testimony offered by the Commonwealth in the instant case failed to meet even this test.
¶4The issue is not one of temporal remoteness, that is, whether evidence that the appellant was sane 33 months prior to the time in question is relevant. The question is even further removed, it is whether the failure to raise an insanity defense at such a prior time in answer to a different offense is relevant to refute a present claim of insanity. I cannot find that such a fact has any probative value whatsoever in the instant proceeding.
¶5However, although objection was made at trial, defense counsel did not raise this issue in post-trial motions. Therefore, it cannot be considered on appeal, Benson v. Penn Central Transp. Co., 463 Pa. 37, 342 A.2d 393 (1975), and the judgment must be affirmed.
¶6Watkins, P.J., joins in this concurring opinion.
¶7Concurring and Dissenting Opinion by
¶8I agree with Judge Jacobs’s opinion that the court below erred in admitting the testimony of the former assistant district attorney; the difficulty I have is with respect to waiver. If Judge Jacobs is correct, that the propriety of admitting the testimony was not raised in post-trial motions, then I agree with him that the issue was waived and so cannot be considered on appeal. However, as Judge Cercone notes in his opinion, perhaps the issue was raised in post-trial motions, not in writing but by oral argument; if it was, then it has not been waived, and, as would Judge Cercone, I would reverse. The question thus presented is simply one of fact, easily answered. Therefore, I would defer our decision until we have been advised by the court below whether the issue was orally raised. If the court reported that it was not raised, I would join Judge Jacobs, if the court reported that it was raised, I would join Judge Cercone.