
301 S.E.2d 421 (1983)
STATE of North Carolina
v.
Carroll Dean BROOKS.
No. 8227SC784.
Court of Appeals of North Carolina.
April 5, 1983.
*422 Atty. Gen. Rufus L. Edmisten by Asst. Atty. Gen. Alfred N. Salley, Asheville, for the State.
Appellate Defender Adam Stein by Asst. Appellate Defender Lorinzo L. Joyner, Raleigh, for defendant-appellant.
VAUGHN, Chief Judge.
Defendant's five assignments of error are presented in three arguments. He first assigns as error the trial judge's overruling his objection to a question the State asked Deputy Sheriff Craig on direct examination. The question was "did you know Mr. Brooks prior to this?" Craig answered, "Yes, sir." Defendant argues that the question was improper because Craig's prior knowledge of defendant implied that defendant had either committed or had been suspected of having committed other, unrelated offenses. This argument is without merit. Craig's knowledge of defendant was relevant to show that he had properly identified defendant. Craig and the defendant lived in a small town. That they knew each other in no way implied defendant had been involved in prior criminal activity. We find no error in the guilt determination part of defendant's trial.
Defendant's remaining assignments of error concern the trial judge's finding aggravating factors and his imposition of a sentence in excess of the presumptive term in the sentencing hearing. Defendant contends, and we agree, that the trial judge erred in finding as a factor in aggravation that defendant was armed with or used a deadly weapon. "Evidence necessary to *423 prove an element of the offense may not be used to prove any factor in aggravation...." G.S. 15A-1340.4(a)(1). Clearly, the rifle was evidence necessary to prove an element of the offense of discharging a firearm into occupied property, and was improperly used to prove an aggravating factor.
Defendant's next argument is that the trial judge's finding as a factor in aggravation that he had prior convictions was improper. He contends G.S. 15A-1340.4(e), which provides that "[a] prior conviction may be proved by stipulation of the parties or by the original or a certified copy of the court record of the prior conviction," precludes proof by any other method.
Defendant failed to object when his record, which he contends was not shown to be an original or certified copy, was handed to the trial judge at the sentencing hearing. The failure to object to the introduction of evidence constitutes a waiver of the right to object, and the admission of the evidence is not a proper basis for appeal. Rule 10(b)(1), Rules of Appellate Procedure; State v. Wilkins, 297 N.C. 237, 254 S.E.2d 598 (1979). Moreover, the language of G.S. 15A-1340.4(e) is permissive rather than mandatory and does not preclude other methods of proof. State v. Massey, 59 N.C.App. 704, 298 S.E.2d 63 (1982).
Defendant assigns as error the trial judge's imposition of a sentence in excess of the presumptive term. Upon a finding that aggravating factors outweigh mitigating factors by the preponderance of the evidence, it is within the trial judge's discretion to decide whether to increase the sentence above the presumptive term, and to what extent. State v. Davis, 58 N.C.App. 330, 293 S.E.2d 658, review denied, 306 N.C. 745, 295 S.E.2d 482 (1982). In this situation, however, where one of the two aggravating factors was improperly considered, the judge exercised his discretion in the light of that misapprehension. State v. Ahearn, ___ N.C. ___, 300 S.E.2d 689 (596A82) (filed 8 March 1983). The judgment imposing sentence must be vacated and the case remanded for resentencing.
Vacated and remanded.
WELLS and BRASWELL, JJ., concur.
