Defendant first contends that the trial court erred in permitting the State to cross-examine him about “another robbery,” arguing that such questioning “exceeded the scope of permissible cross-examination and [was without] good faith basis.” *119 State v. Mack, 282 N.C. 334, 341-42, 193 S.E. 2d 71, 76 (1972). The purpose of permitting disparaging questions concerning collateral matters relating to a defendant’s criminal and degrading conduct is to allow the jury to consider the defendant’s acts and conduct in weighing his or her credibility. The testifying defendant is not without some protection, however, since the questions must concern a specific, identifiable act of defendant, State v. Dawson, 302 N.C. 581, 276 S.E. 2d 348 (1981), and “the questions asked by the prosecutor must be based on information and must be asked in good faith.” State v. Pilkington, 302 N.C. 505, 510, 276 S.E. 2d 389, 393, cert. denied, 454 U.S. 850 (1981). Defendant bears the burden of showing bad faith. State v. Dawson, 302 N.C. 581, 276 S.E. 2d 348 (1981).
*118It has long been the rule that where a defendant in a criminal case testifies in his own behalf, specific acts of misconduct may be brought out on cross-examination to impeach his testimony. [Citations omitted.] Such “cross-examination for the purpose of impeachment is not limited to conviction of crimes. Any act of the witness which tends to impeach his character may be inquired about or proven by cross-examination.” State v. Sims, 213 N.C. 590, 197 S.E. 176 (1938). Although a defendant may not be asked if he has been accused, arrested or indicted for a particular crime, State v. Williams, 279 N.C. 663, 185 S.E. 2d 174 (1971), he may be asked if he in fact committed the crime.
*119The questioning alleged by defendant to have been improper appears in the transcript as follows:
Q. On the night of May 27, 1982, Mr. Cunningham, didn’t you rob Michael Boyles at the Axton-Cross Company at 9:30 that evening on Service Road in Charlotte?
Mr. Rawls: Objection.
The Court: Overruled.
Mr. Rawls: Objection.
The Court: Overruled.
A. No, ma’am.
Q. Earlier that evening on that very same date, isn’t it true, Mr. Cunningham, that you robbed William Galloway on North Graham Street in Charlotte by asking him first about a job and pulling a gun on him and later firing that gun in a struggle with him?
A. No, ma’am.
Mr. Rawls: Objection.
The Court-. Overruled.
Following this interchange, the court conducted a voir dire on the question of the State’s good faith basis for inquiring about the Galloway robbery and found as a fact that such good faith basis existed. In regard to the Boyles robbery, the transcript contains *120the following statement by defense counsel: “I will stipulate that in the Boyles case there is a good-faith basis for asking that question.” We thus turn our attention to the narrow question whether defendant has sustained his burden of showing that the State did not act in good faith in asking defendant for impeachment purposes whether he robbed William Galloway.
The State’s argument, which we find persuasive, is that a good faith basis for inquiry about the Galloway robbery may be found in its significant similarities to the Lazinsky robbery, with which defendant was charged. The record reveals that both offenses, as well as the Boyles robbery, occurred in the same geographic area between 9:30 and 11:30 p.m. on the same night; the defendant was identified as the perpetrator of the other two robberies; the perpetrator of the Galloway robbery fit the general description of defendant; in all three robberies, the perpetrator first engaged the victims, who were working, in seemingly innocent conversation prior to pulling a gun on them; and, in the Galloway and Lazinsky robberies, the perpetrator asked the victims about a job prior to robbing them. We think this information was ample to provide the State with a good faith basis for asking defendant whether he in fact committed the Galloway robbery. While, as Professor Brandis points out, “the unconvicted defendant [is unlikely to] admit the criminal acts charged,” 1 Brandis on North Carolina Evidence Sec. 112, n. 61 (1982), this common sense observation in no way changes the well-established law of this State. The assignment of error is without merit.
 Defendant next contends that the court erred in allowing the State to introduce evidence during the rebuttal stage of the trial tending to show that defendant committed the Boyles robbery. Defendant argues that extrinsic evidence of other crimes is not admissible for impeachment purposes, and that such evidence was inadmissible for any other purpose.
It is true, as defendant states, that extrinsic evidence of prior bad acts is not admissible for the purpose of contradicting defendant’s denial of such acts on cross-examination. State v. Robinette, 39 N.C. App. 622, 251 S.E. 2d 635 (1979). The rule regarding substantive use of prior offenses is equally clear, and is set out in Brandis as follows: “Evidence of other offenses is inadmissible on the issue of guilt if its only relevancy is to show the *121character of the accused or his disposition to commit an offense of the nature of the one charged; but if it tends to prove any other relevant fact it will not be excluded merely because it also shows him to have been guilty of an independent crime.” 1 Brandis on North Carolina Evidence Sec. 91 (1982). Because we believe the challenged evidence was properly admitted as tending to prove the disputed issue of identity, we find no error.
Our decision in this regard finds support in the decisions of our Supreme Court in State v. Freeman, 303 N.C. 299, 278 S.E. 2d 207 (1981) and State v. Leggett, 305 N.C. 213, 287 S.E. 2d 832 (1982). In both Freeman and Leggett the Court upheld the admission of evidence tending to show that defendant therein committed another separate offense as bearing on identity in the case being tried, where identity was a disputed issue in the case. In our view, the similarities between the Boyles and Lazinsky robberies were even greater and more substantial than the similarities of the offenses in Leggett. In Leggett, each victim had identified the defendant as her assailant. Although the Leggett Court said nothing about any similarity of the descriptions of the assailant, the Court had this to say about the similarity of the manner in which the attacks occurred:
The accounts by Miss Martin and Miss Mosely of the attacks against them revealed many similarities in the manner in which each of them was attacked, even though the attacks occurred one month apart. In each case the perpetrator came from a parking area in the vicinity of a church and grabbed a teenage woman on the public streets. In each case the perpetrator held a knife on the victim and proceeded to drag her to a secluded area from which he had more than one route of escape. The manner in which the perpetrator in each situation exposed himself to the young woman while holding a knife on her as well as the manner of his demands that they commit sexual acts with him were substantially the same.
Id. at 224, 287 S.E. 2d at 839. The Supreme Court’s conclusion in Leggett — “If the evidence complained of tended to show that the attack on Miss Martin and another offense were committed by the same person, evidence that the defendant committed the other offense was admissible to identify him as Miss Martin’s attacker,” *122 id. at 223, 287 S.E. 2d at 838 — compels the same result in this case.
We summarily reject defendant’s final arguments concerning his sentence. First, there has been no showing by defendant that the trial court considered the defendant’s potential release date or elements of the offense for which defendant was charged in sentencing defendant. Second, our Supreme Court’s decision in State v. Thompson, 309 N.C. 421, 307 S.E. 2d 156 (1983), rejects and disposes of defendant’s contention that the State is obligated to prove defendant’s non-indigency or representation by counsel at the time of prior convictions.
For the reasons stated above, we find
Judge ARNOLD concurs.
Judge BECTON dissents.