Sub-paragraph 1 of Section 51 of Rule 130 provides that the accused may prove his good moral character which is pertinent to the moral trait involved in the offense charged. When the accused presents proof of his good moral character, this strengthens the presumption of innocence, and where good character and reputation are established, an inference arises that the accused did not commit the crime charged. This view proceeds from the theory that a person of good character and high reputation is not likely to have committed the act charged against him.
Sub-paragraph 2 provides that the prosecution may not prove the bad moral character of the accused except only in rebuttal and when such evidence is pertinent to the moral trait involved in the offense charged. This is intended to avoid unfair prejudice to the accused who might otherwise be convicted not because he is guilty but because he is a person of bad character. The offering of character evidence on his behalf is a privilege of the defendant, and the prosecution cannot comment on the failure of the defendant to produce such evidence. Once the defendant raises the issue of his good character, the prosecution may, in rebuttal, offer evidence of the defendant’s bad character. Otherwise, a defendant, secure from refutation, would have a license to unscrupulously impose a false character upon the tribunal. Both sub-paragraphs (1) and (2) of Section 51 of Rule 130 refer to character evidence of the accused. And this evidence must be "pertinent to the moral trait involved in the offense charged," meaning, that the character evidence must be relevant and germane to the kind of the act charged, e.g., on a charge of rape, character for chastity; on a charge of assault, character for peacefulness or violence; on a charge for embezzlement, character for honesty and integrity.