dissenting:
Walter Norman was tried by jury and was found guilty of aggravated assault and possession of an instrument of crime in connection with the shooting of his former girlfriend, Cassandra Harris. On direct appeal from the judgment of sentence, he argues that it was error (1) to allow evidence of prior criminal conduct which had caused the disaffection between himself and Cassandra Harris; and (2) to permit an expression of opinion by a police officer that appellant was dangerous. The majority holds, and I agree, that reference to appellant’s prior criminal conduct was properly received to show motive and also to show the relationship between appellant and the victim and the dispute between them which culminated in the shooting. However, I am unable to agree with the majority’s determination of the second issue. I would hold that it was error to allow the jury to hear evidence of the investigating police officer’s opinion that appellant was a dangerous person. Because this error cannot be deemed harmless, I would *222reverse the judgment of sentence and remand for a new trial.
Harris and Norman had been romantically involved and had lived together for two years. They separated after Norman was arrested for the December, 1980, kidnap, rape, and robbery of two women. Harris not only refused to provide Norman with an alibi, as he had requested, but also cooperated with investigating police. Norman, although arrested and charged, failed to appear at the preliminary hearing and became a fugitive.
On the morning of May 13, 1981, he appeared in front of Harris’s apartment and offered to give her a ride to work. She accepted. During the ride, Norman asked Harris to resume their prior relationship and flee the jurisdiction with him. Harris refused, and an argument ensued. According to the trial testimony of Harris, appellant told her there was only one thing to do, reached into the back seat, and retrieved a gun. After a brief struggle, appellant was able to hold Harris down and then shot her in the neck. Harris, although seriously hurt, did not lose consciousness. Because she knew Norman was a fugitive and therefore could not take her to a hospital, she asked to be taken to a place where she would be found. Norman took her to a gasoline service station, where she was found and removed to a hospital. Harris is now a permanent quadriplegic. Appellant’s testimony at trial was that he had borrowed the car from a friend and did not know that there was a gun in it. He testified that the gun had come into view when a sudden lurch caused an armrest to fall. He contended further that the gun had discharged accidentally during a struggle to retrieve it.
The manner in which the shooting occurred depended primarily on the conflicting testimonies of Harris and Norman. The credibility of the two witnesses, therefore, was an important determination to be made by the jury.
Evidence of prior crimes and/or acts of violence is inadmissible to prove a defendant’s propensity for violence or bad character. Commonwealth v. Banks, 513 Pa. 318, 349, *223521 A.2d 1, 17 (1987); Commonwealth v. Morris, 493 Pa. 164, 175, 425 A.2d 715, 720 (1981). However, evidence of prior crimes or violent acts may be admissible where it is relevant for some other legitimate purpose. Commonwealth v. Banks, supra; Commonwealth v. Claypool, 508 Pa. 198, 204, 495 A.2d 176, 178 (1985). Among the several exceptions to the general rule is that which permits evidence of prior criminal conduct to show motive.
In this case, it was the contention of the Commonwealth that the shooting had not been accidental but intentional. It had been committed, according to the Commonwealth, in retaliation for the victim’s refusal to supply appellant with an alibi in the prior criminal proceedings and because of her refusal to flee with him in order to avoid prosecution. The prior criminal charges, therefore, were relevant to show motive. In order to minimize the harm from this evidence, however, the trial court did not permit the jury to learn of the nature of the prior crimes; the jurors learned only that appellant had committed a crime against two women and that the crime had been committed in Harris’s apartment. Moreover, the jurors were carefully instructed on the limited use to be made of this evidence.
Under these circumstances, the trial court did not err. Appellant’s prior criminal conduct was an essential part of the Commonwealth’s case and necessary to the jury’s understanding of the circumstances surrounding the shooting.
The second issue concerns an evidentiary ruling by the trial court which permitted Detective Peter Piefer to testify, over objection, that while Norman was a fugitive on the prior charges, he, Piefer, had told Harris, “to be careful because I thought Walter Norman was dangerous.” (emphasis added). Appellant contends that the ruling was erroneous and that the detective’s opinion that appellant was dangerous was unfairly prejudicial. I agree.
The objectionable testimony consisted of the witness’s opinion about the defendant’s character. However, the defendant’s character was not an issue in the case, and the *224detective’s opinion regarding the defendant’s character was irrelevant and inadmissible. As a general rule, “[t]he character of the defendant is not in issue in a criminal proceeding until the accused himself does something which puts it in issue.” 10A P.L.E., Criminal Law § 361. See: Commonwealth v. Anthony, 91 Pa.Super. 518, 521 (1927). In a criminal prosecution, the factfinder’s concern is with what the defendant did and why it was done, and evidence of his general character, having only slight probative value and great potential for prejudice, is inadmissible. McCormick on Evidence §§ 186, 188 (3d ed. 1984). Cf. Commonwealth v. Tirado, 473 Pa. 468, 375 A.2d 336 (1977). Moreover, when the defendant’s character is in issue and, therefore, relevant, it must be proved by evidence of his reputation or by evidence of conduct which reflects a character trait. The personal opinion of the witness is not admissible to prove the character of the defendant. See: Commonwealth v. Neely, 372 Pa.Super. 519, 524, 539 A.2d 1317, 1320 (1988); Commonwealth v. Gaines, 167 Pa.Super. 485, 490, 75 A.2d 617, 619 (1950).
The Commonwealth argues that even if the trial court’s ruling was incorrect, it was harmless. “[A]n error may be harmless where the properly admitted evidence of guilt is so overwhelming and the prejudicial effect of the error is so insignificant by comparison that it is clear beyond a reasonable doubt that the error could not have contributed to the verdict.” Commonwealth v. Story, 476 Pa. 391, 412, 383 A.2d 155, 166 (1978). In the instant case, the undisputed evidence was that Harris had been seriously injured as a result of the shooting. Appellant did not deny this fact. Whether the defendant had gone gunning for the victim and shot her deliberately and intentionally in retaliation for her cooperation with police in the prior incident or whether he had sought her out to discuss their personal relationship and subsequently engaged in a dispute which resulted in an accidental shooting, however, was a question of fact for the jury. In order to resolve this issue the jury was necessarily required to determine the credibility of the victim and the defendant, for they were the only persons present at the *225time of the shooting. Under these circumstances, it cannot be said beyond a reasonable doubt that the opinion of an experienced police officer that appellant was a dangerous person did not have an effect on the jurors’ decision.1
Before submitting the case to the jury for decision, the trial judge sua sponte asked defense counsel if he desired a cautionary instruction to be given to the jury regarding the detective’s opinion that appellant was a dangerous person. Defense counsel declined the trial court’s offer which, of necessity, would have repeated or at least reminded the jury of the police officer’s opinion. The majority holds that the defendant is thereby precluded from asserting prejudice. I must disagree. In the first place, the suggested instruction was too late. The jury had already heard the trial court rule that the evidence was properly for it to consider. Secondly, it is wholly unrealistic to believe that a jury which has been permitted to hear prejudicial evidence, with the trial court’s erroneous imprimatur, can wash such evidence from its collective mind by a belated “cautionary instruction.” “[Cjurative instructions do not, without exception, cure.” Commonwealth v. Channell, 335 Pa.Super. 438, 454, 484 A.2d 783, 791 (1984). Finally, the rule espoused by the majority puts the defendant in an untenable position. A defendant who has been harmed by an erroneous evidentiary ruling must either consent to having the prejudicial matter repeated by the trial court or surrender the right to obtain post-trial and appellate review of the trial court’s ruling. The rule advanced by the majority, I submit, is an alarming and unwarranted incursion into the right of an accused to receive a fair trial. Therefore, I dissent. “When an error in a trial is of such consequence that, like a dash of ink in a can of milk, it cannot be strained out, the only remedy, so that justice may not ingest a tainted fare, is a new trial.” Commonwealth v. Gaerttner, 335 Pa.Super. *226203, 220, 484 A.2d 92, 101 (1984), quoting Lobalzo v. Varoli, 409 Pa. 15, 21, 185 A.2d 557, 561 (1962).
I would reverse and remand for a new trial.
. The detective’s opinion testimony was not merely repetitive of prior testimony by the victim. Although she testified that she had been warned by the police to be careful because she had cooperated in the investigation of the prior offense, there was no prior testimony that the police, or any one of them, considered appellant to be a dangerous or violent person.