The position of the law is very much unequivocal on the issue. As copiously alluded heretofore, evidence of the fact that a defendant is of bad character is generally inadmissible in a criminal proceeding. However, there are some exceptions to this general principle. The fact that a defendant is of bad character becomes admissible: (a) When the bad character of the defendant is a fact in issue; or (b) when the defendant (unwittingly) has given evidence of good character thereof. A defendant may equally be asked questions to show that he is of bad character in the circumstances mentioned in paragraph (c) of the proviso to Section 180 of the Evidence Act. The hallmark of these exceptions is that whenever evidence of bad character is admissible, evidence of previous conviction becomes equally admissible.
– Saulawa, JSC. Makanjuola v. State (2021)