Among the numerous assignments of error identified and argued before us by defendant, one particularly merits our scrutiny *281and discussion: the use of photographs and slides of the victims’ bodies to illustrate the testimony of witnesses for the state.
We only find it necessary to summarize the evidence with respect to the dispositive issue on this appeal. Shortly after noon on Sunday, 12 May 1985, neighbors concerned that they had not seen Kathryn Eastburn or her three children since Thursday night fruitlessly rang the doorbell and knocked on several doors to the Eastburn home. The failure of Mrs. Eastburn to come to the door and the sound of what they thought was a baby’s cry prompted the neighbors to call the sheriffs department. The deputy sheriff who responded to their call repeated their attempts to arouse inhabitants and, in circling the house to find an open door or window, saw a child inside standing in her crib. He cut the screen on the window and entered the house, passing the child out to a waiting neighbor.
The officer opened the door to the hall and walked through the house to the master bedroom where he discovered the body of three-year-old Erin Eastburn and the naked body of her mother on the floor. The officer noted that there were numerous knife wounds to the chests of both victims and that part of the child’s face and chest and Mrs. Eastburn’s face were covered with pillows. On the bed in a second bedroom the officer found the body of five-year-old Kara Eastburn, also with numerous knife wounds to her chest and side and a pillow or blanket over her head.
Autopsies of the three victims revealed that the cause of death of all three had been stab wounds and a large cut in the neck of each. The autopsies also revealed bruising and abrasions and “defensive type” wounds to the hands and forearms of one or more of the victims. In addition, Mrs. Eastburn’s wrists showed marks consistent with their having been tied, and vaginal swabs revealed the presence of sperm deposited within hours of her death.
Evidence linking defendant to the crime was chiefly circumstantial. Despite the fact that investigators examining the East-burn home discovered fingerprints and one Caucasian pubic hair that belonged to none of the Eastburn family members, these and the analysis of bloodstains and of the sperm from Mrs. Eastburn’s vagina failed to reveal any match with defendant’s physical characteristics. The only direct evidence implicating defendant *282was the testimony of a neighbor who had been walking by the Eastburn house at 3:30 a.m. on Friday morning, and who saw a man he later identified as defendant walking down the Eastburn’s driveway and toting a plastic garbage sack. The tenuousness of this identification was apparent in that the witness revised his impression of the stature and build of the man he said he had seen from one shorter and slighter than himself to one of defendant’s build — one considerably taller and heavier than the witness’s own.
A second witness testified that she had seen a man who looked like defendant getting into a small light-colored car in the vicinity of the bank where Mrs. Eastburn’s bank card had been used Saturday morning, 11 May. This witness’s identification of defendant was extremely tentative, however: when asked by investigators in late June or early July whether she had seen anyone near the bank that Saturday morning, she had replied that she “had not seen anyone.” It wasn’t until the following April that she recalled having seen anyone, and when she picked defendant’s photograph out of a lineup, she admitted that she was not sure whether she was identifying him from the newspapers or from seeing him at the bank that morning.
The state made ninety-nine photographs of the crime scene and of the bodies at the autopsy. These were subjected to a pretrial motion filed by defendant requesting that the use of the photographs of the victims be prohibited, or, in the alternative, that it be restricted to one photograph per victim, and that the trial court review the state’s intended use of the photographs with an eye to possible excess. Pursuant to the motion, the trial court reviewed the photographs and concluded that thirty-five crime scene and autopsy photographs could be offered at trial.
The state made duplicate slides of the thirty-five acceptable photographs and the trial court subsequently authorized the construction of a screen large enough to project two images 3 feet 10 inches by 5 feet 6 inches side-by-side on the courtroom wall opposite the jury. This design permitted the jury to view the slides projected just above defendant’s head.
Nine slides depicting the victims’ bodies at the crime scene were used to illustrate the testimony of the deputy sheriff who discovered the bodies and of the paramedic who arrived shortly *283afterwards. Despite the fact that defendant had signed stipulations as to the cause of the victims’ deaths that tracked the autopsy reports, twenty-six slides of the bodies taken at the autopsy were used by forensic pathologists to illustrate their testimony as to the nature and extent of the wounds.
The thirty-five 8-by-10-inch glossy photographs, the majority of which were in color, were subsequently distributed, one at a time, to the jury. This process took a full hour and was unaccompanied by further testimony. The autopsy photographs generally depicted the head and chest areas of the victims and revealed in potent detail the severity of their wounds, made all the more gruesome by the visible protrusion of organs, caused by process of decomposition. The trial court’s charge to the jury shortly before it retired to consider its verdicts included the admonition that the photographs and other illustrative evidence were to be used “for the purpose of illustrating and explaining the testimony of the various witnesses. . . . [and that they were not to] be considered ... for any other purpose.”
Defendant asserts that the state’s use of slides and photographs of the victims’ bodies addressed and impressed the emotions of the jury more forcefully than its logic and that, because the probative value of such evidence was far outweighed by its prejudicial impact, he was deprived of a fair trial.
[1,2] The admissibility of evidence, including photographic evidence, is governed by Rule 403 of the North Carolina Rules of Evidence, which states:
Although relevant, evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.
N.C.G.S. § 8C-1, Rule 403 (1986). “Unfair prejudice” means an undue tendency to suggest a decision on an improper basis, usually an emotional one. State v. Mason, 315 N.C. 724, 340 S.E. 2d 430 (1986). Photographs are usually competent to explain or illustrate anything that is competent for a witness to describe in words, State v. Holden, 321 N.C. 125, 362 S.E. 2d 513 (1987), cert. denied, --- U.S. ---, 100 L.Ed. 2d 935 (1988), and properly authenticated *284photographs of a homicide victim may be introduced into evidence under the trial court’s instructions that their use is to be limited to illustrating the witness’s testimony. Id.; State v. Watson, 310 N.C. 384, 312 S.E. 2d 448 (1984). Thus, photographs of the victim’s body may be used to illustrate testimony as to the cause of death, State v. Williams, 308 N.C. 47, 301 S.E. 2d 335, cert. denied, 464 U.S. 865, 78 L.Ed. 2d 177, reh’g denied, 464 U.S. 1004, 78 L.Ed. 2d 704 (1983). Photographs may also be introduced in a murder trial to illustrate testimony regarding the manner of killing so as to prove circumstantially the elements of murder in the first degree, State v. Lester, 294 N.C. 220, 240 S.E. 2d 391 (1978), and for this reason such evidence is not precluded by a defendant’s stipulation as to the cause of death. State v. Elkerson, 304 N.C. 658, 285 S.E. 2d 784 (1982). Photographs of a homicide victim may be introduced even if they are gory, gruesome, horrible or revolting, so long as they are used for illustrative purposes and so long as their excessive or repetitious use is not aimed solely at arousing the passions of the jury. State v. Murphy, 321 N.C. 738, 365 S.E. 2d 615 (1988); State v. King, 299 N.C. 707, 264 S.E. 2d 40 (1980).
This Court has recognized, however, that when the use of photographs that have inflammatory potential is excessive or repetitious, the probative value of such evidence is eclipsed by its tendency to prejudice the jury. Thus, this Court has concluded that photographs taken in the funeral home of a murder victim’s body were “poignant and inflammatory” where the evidence tended to show that the victim had been lying on a bed when shot and when the evidence as to the cause of his death was uncontradicted. State v. Mercer, 275 N.C. 108, 121, 165 S.E. 2d 328, 337 (1969), overruled on other grounds, State v. Caddell, 287 N.C. 266, 215 S.E. 2d 348 (1975).
And this Court has repeatedly warned against the redundant or excessive use of photographs of victims’ bodies:
But where a prejudicial photograph is relevant, competent and therefore admissible, the admission of an excessive number of photographs depicting substantially the same scene may be sufficient ground for a new trial when the additional photographs add nothing in the way of probative value but tend solely to inflame the jurors.
*285 State v. Mercer, 275 N.C. 108, 120, 165 S.E. 2d 328, 337, quoted in State v. Johnson, 298 N.C. 355, 377, 259 S.E. 2d 752, 765 (1979). See also State v. Sledge, 297 N.C. 227, 231-32, 254 S.E. 2d 579, 583 (1979) (despite finding no prejudicial error, the Court admonished the state that it “likely could have illustrated the medical testimony fully as well with fewer pictures. Excessive use of photographs is not favored.”).
 In general, the exclusion of evidence under the balancing test of Rule 403 of the North Carolina Rules of Evidence is within the trial court’s sound discretion. State v. McLaughlin, 323 N.C. 68, 372 S.E. 2d 49 (1988); State v. Mason, 315 N.C. 724, 340 S.E. 2d 430. Whether the use of photographic evidence is more probative than prejudicial and what constitutes an excessive number of photographs in the light of the illustrative value of each likewise lies within the discretion of the trial court. State v. Sledge, 297 N.C. 227, 254 S.E. 2d 579. Abuse of discretion results where the court’s ruling is manifestly unsupported by reason or is so arbitrary that it could not have been the result of a reasoned decision. State v. Parker, 315 N.C. 249, 337 S.E. 2d 497 (1985).
 The test for excess is not formulaic: there is no bright line indicating at what point the number of crime scene or autopsy photographs becomes too great. The trial court’s task is rather to examine both the content and the manner in which photographic evidence is used and to scrutinize the totality of circumstances composing that presentation. What a photograph depicts, its level of detail and scale, whether it is color or black and white, a slide or a print, where and how it is projected or presented, the scope and clarity of the testimony it accompanies — these are all factors the trial court must examine in determining the illustrative value of photographic evidence and in weighing its use by the state against its tendency to prejudice the jury. See State v. Banks, 564 S.W. 2d 947 (Tenn. 1978). In addition, the trial court must probe the relevance of the scene depicted and conclude that its irrelevant portions do not obscure those elements that are pertinent to the proffered testimony. See, e.g., State v. Johnson, 298 N.C. 355, 259 S.E. 2d 752 (where there was no evidence that the defendant had mutilated or dismembered the body of the deceased, photographs of the victim’s body after its having been ravaged by animals not probative of any material fact at issue); State v. Mercer, 275 N.C. 108, 165 S.E. 2d 328 (funeral home photographs). *286Finally, critical to the trial court’s inquiry into the admissibility of a photograph is the determination that it does not unduly reiterate illustrative evidence already presented. When a photograph “add[s] nothing to the State’s case,” State v. Temple, 302 N.C. 1, 14, 273 S.E. 2d 273, 281 (1981), then its probative value is nil, and nothing remains but its tendency to prejudice.
 In spite of the trial court’s appropriate determination that many of the photographs initially proffered by the state were repetitious and the court’s consequential ruling that these could not be admitted into evidence, many other photographs with repetitive content were allowed. The record reflects such repetition even in the testimony of one of the pathologists, who at one point had nothing to say concerning a slide depicting a child’s neck wound except to identify it and add, “This looks like the one we saw before.” Likewise, the several color images of the same victim’s neck wound taken at the autopsy cannot be said to have added anything in the way of probative value to the color images of that same wound taken at the crime scene and projected before the jury in illustration of the previous testimony, even when the witness was testifying to different facts. Although this Court has not disapproved the illustrative use of autopsy photographs, e.g., State v. Sledge, 297 N.C. 227, 254 S.E. 2d 579, the majority of the twenty-six photographs taken at the victims’ autopsies here added nothing to the state’s case as already delineated in the crime scene slides and their accompanying testimony. Given this absence of additional probative value, these photographs — grotesque and macabre in and of themselves — had potential only for inflaming the jurors. State v. Murphy, 321 N.C. 738, 365 S.E. 2d 615.
In addition, the prejudicial effect of photographs used repetitiously in this case was compounded by the manner in which the photographs were presented. The erection of an unusually large screen on a wall directly over defendant’s head such that the jury would continually have him in its vision as it viewed the slides was a manner of presentation that in itself quite probably enhanced the prejudicial impact of the slides themselves. Finally, the thirty-five duplicative photographs published to the jury one at a time just before the state rested its case were excessive in both their redundancy and in the slow, silent manner of their presentation. We hold that under the facts of this case, permit*287ting the photographs with redundant content to be admitted into evidence and to be twice published to the jury was error.
Only upon a showing that the trial court erred and that defendant has been prejudiced thereby will defendant be granted a new trial. In State v. Johnson, 298 N.C. 355, 259 S.E. 2d 752, and in State v. Temple, 302 N.C. 1, 273 S.E. 2d 273, the unnecessary or repetitive use of photographic evidence was held to be harmless where the evidence of defendant’s guilt was overwhelming. This is not such a case. Here defendant was linked to the crime through circumstantial evidence and through direct evidence upon which the witnesses’ own remarks cast considerable doubt. Overwhelming evidence of his guilt was not presented. He was nonetheless found guilty and sentenced to death. Under N.C.G.S. § 15A-1443(a) (1983), reversible error occurs when the defendant shows “there is a reasonable possibility that, had the error in question not been committed, a different result would have been reached at the trial out of which the appeal arises.” Id. In view of the verdicts and sentences handed down in defendant’s trial, it cannot be said that this error, which tended to inflame the passions of the jury, was not prejudicial. We accordingly hold that defendant is entitled to a new trial. Defendant brings forward and argues many additional assignments of error, both as to the guilt phase and the sentencing phase of this trial. However, in view of our disposition of this appeal, we do not find it necessary to address defendant’s remaining assignments of error, confident that such alleged errors are not likely to recur upon retrial.