THE STATE OF SOUTH CAROLINA
In The Court of Appeals
The State, Respondent,
Christopher Owens, Appellant.
Appeal From Sumter County
Howard P. King, Circuit Court Judge
Unpublished Opinion No. 2003-UP-669
Submitted October 6, 2003 – Filed November 17, 2003
Assistant Appellate Defender Robert M. Dudek, of Columbia, for Appellant.
Attorney General Henry Dargan McMaster, Chief Deputy Attorney General John W. McIntosh, Assistant Deputy Attorney General Charles H. Richardson, Assistant Attorney General David A. Spencer, all of Columbia; and Solicitor Cecil Kelly Jackson, of Sumter, for Respondent.
Per Curiam: Christopher Owens was convicted for first-degree burglary, armed robbery, and conspiracy. He was sentenced to twenty-five-years imprisonment for burglary, fifteen-years imprisonment for armed robbery, and five-years imprisonment for conspiracy, the sentences to run concurrently. Owens appeals, arguing the trial court erred by: 1) failing to order a mental evaluation to determine his competency to stand trial; and 2) excluding testimony regarding his competency to stand trial. We affirm.
Owens was indicted in 1998 for murder, first-degree burglary, first-degree criminal sexual conduct, robbery, and conspiracy. Thereafter, more than two years elapsed before his trial, during which time Owens changed attorneys on several occasions.
When the case was called for trial in 2000, Owens’ newly obtained counsel made a motion for Owens to undergo a mental evaluation to determine his competency to stand trial. In support of this motion, Owens’ counsel argued that although none of Owens’ previous attorneys had requested a mental evaluation, he was concerned with Owens’ competency because Owens exhibited signs of mental instability during the previous weekend.
Owens’ counsel presented two documents to support his motion. The first, a medical evaluation in May 1997 by Psychiatrist B.J. Ramsey, stated Owens was admitted to a psychiatric institute at age fourteen because he attempted to commit suicide. The report indicates Owens’ suicide attempts were based, in part, on Owens’ auditory hallucinations in the form of discussions with his dead uncle. The report noted the alleged discussions did not have negative messages and did not include any suggestions to Owens that he cause harm to himself or others.
The report also indicated Owens was previously diagnosed with major depressive disorder and that at discharge Owens was taking Zoloft, as well as Zyprexa.
The second report, a January 1998 report by Psychologist Tammy Morris ordered following Owens’ arrest, indicates Owens was a mildly mentally disabled fifteen-year-old adolescent. Additionally, it indicates Owens continues to experience auditory hallucinations in the form of conversations with his dead uncle. The report indicates Owens’ conversations with the dead uncle were positive and did not involve suggestions to Owens to hurt himself or others. According to the report, the hallucinations were the result of depression, and not psychosis.
The report also indicated Owens continues to take Zoloft and Zyprexa, as well as Vistaril, but further indicates Owens was cooperative, attentive, focused, responsive to questions, and able to conform his behavior to acceptable societal norms.
Following introduction of the reports, the circuit court conducted an examination of Owens, and, noting the affidavits and its own questioning of Owens, found a mental evaluation was not required. The court observed that Owens was “oriented,” knowledgeable of the charges presented against him, and able to participate in his own defense.
After the circuit court ruled on the motion, Owens’ counsel moved for the first time to hear from Owens’ grandmother, Hattie Owens, on the issue of competency. The circuit court denied counsel’s request, citing Rule 18, South Carolina Rules of Criminal Procedure. 
Owens was subsequently convicted for first-degree burglary, armed robbery, and conspiracy. Owens appeals.
I. Mental Evaluation
Owens argues the circuit court erred by failing to order a mental evaluation pursuant to South Carolina Code Annotated section 44-23-410 (2002). We disagree.
Due process prohibits the conviction of a person who is mentally incompetent. Jeter v. State, 308 S.C. 230, 232, 417 S.E.2d 594, 595 (1992). Accordingly our legislature has established procedures to determine when an individual must undergo mental evaluations to determine their competency to stand trial. See S.C. Code Ann. § 44-23-410. Section 44-23-410 provides “[w]henever a judge . . . has reason to believe that a person on trial before him . . . is not fit to stand trial because the person lacks the capacity to understand the proceedings against him or to assist in his own defense as a result of a lack of mental capacity, the judge shall . . .” order a mental evaluation.
“The statutory injunction, that an examination be ordered when the circuit judge ‘has reason to believe’ that a defendant is not mentally competent to stand trial, involves the exercise of the discretion of the trial judge in evaluating the facts presented on the question of competency.” State v. Drayton, 270 S.C. 582, 584, 243 S.E.2d 458, 459 (1978). A refusal to grant an evaluation will not be disturbed on appeal absent a clear showing of an abuse of discretion. Id.; State v. Singleton, 322 S.C. 480, 483, 472 S.E.2d 640, 642 (Ct. App. 1996).
Owens produced two reports generated between two and three years prior to the trial to support his contentions. Following the introduction of the reports, the circuit court conducted a hearing, questioning Owens to determine that he knew the day of the week, his residence, his physical location, his age, his lawyer’s name, the name of his school, the specific classes he was taking, and why he was in court. Owens answered each question correctly and noted that he was at the courthouse because “[he] was on trial here . . . [charged with] murder for this elderly woman.”
Based on the evidence presented, the circuit court declined to order a mental evaluation of Owens, finding Owens was “oriented as to time and place and the extent of the charges against him.”
We find no clear abuse of discretion. The supporting affidavits presented by Owens indicate that although Owens has some psychological and mental impairment, Owens was cooperative, attentive, focused, and responsive to questions during his evaluation. Furthermore, the circuit court’s hearing indicates the defendant understood the proceedings against him and was capable of assisting in his own defense. This evidence is sufficient to support a finding Owens’ was competent to stand trial. See State v. Reed, 332 S.C. 35, 39-40, 503 S.E.2d 747, 749 (1998) (“The test for determining . . . competency to stand trial is ‘whether . . . [the defendant] has sufficient present ability to consult with his lawyer with a reasonable degree of rational understanding and whether he has a rational as well as a factual understanding of the proceedings against him.’”) (quoting Dusky v. United States, 362 U.S. 402, 402 (1960). Thus, the circuit court did not abuse its discretion in declining to order a mental evaluation pursuant to section 44-23-410.
II. Opportunity to be heard
Owens argues the circuit court erred by excluding his grandmother’s testimony.
The circuit court ruled Owens was competent to stand trial. Thereafter, and for the first time, Owens moved to admit his grandmother’s testimony. The circuit court denied the motion, and Owens timely objected. However, Owens did not proffer the grandmother’s testimony. Thus, the issue is not preserved for appellate review. See State v. Roper, 274 S.C. 14, 20, 260 S.E.2d 705, 708 (1979) (“It is well settled that a reviewing court may not consider error alleged in [the] exclusion of testimony unless the record on appeal shows fairly what the rejected testimony would have been.”); see also State v. Cabbagestalk, 281 S.C. 35, 36, 314 S.E.2d 10, 11 (1984) (failure to make an offer of proof prevents the appellate court from determining whether the exclusion of testimony is prejudicial and thus precludes the appellant from raising the issue on appeal).
Notwithstanding Owens’ failure to make a proffer, Owens contends his grandmother’s testimony during Owens’ suppression hearing four days later was sufficient to provide a proffer because her subsequent testimony was substantially similar to what her testimony would have been during the competency hearing.
During the suppression hearing, Owens’ grandmother testified Owens was mentally and psychologically disabled, as evidenced by his: suicide attempt, admission to a psychiatric institute, auditory hallucinations, low reading level, low cognitive level, and prescriptions for several drugs. Her testimony also indicates Owens’ mental and psychological impairments were less severe at the time of trial than they were when the two previously mentioned reports were generated.
Assuming we accept Owens’ position, Owens’ grandmother’s testimony is substantially similar to the information already presented to the circuit court through the two reports. Furthermore, the circuit court did not question the veracity of the reports or their content, and based its decision, in part, on its own examination of Owens.
Thus, the testimony was at best cumulative, and its exclusion, even if error, was not prejudicial error subject to reversal. See State v. Gaskins, 284 S.C. 105, 117, 326 S.E.2d 132, 140 (1985) (“Error in the exclusion of evidence is not prejudicial where its effect would have been merely cumulative.”); State v. Taylor, 333 S.C. 159, 172, 508 S.E.2d 870, 876 (1998) (holding an appellate court will not reverse a lower court for improperly admitting or excluding evidence unless the error was prejudicial).
For the foregoing reasons, the decision of the circuit court is
STILWELL, HOWARD, and KITTREDGE, JJ., concurring.
 Rule 18(a), South Carolina Rules of Criminal Procedure states: “Counsel shall not attempt to further argue any matter after he has been heard and the ruling of the court has been pronounced.”
 Because oral argument would not aid the Court in resolving any issue on appeal, we decide this case without oral argument pursuant to Rule 215, SCACR.