In Giesberg v. State, 984 S.W.2d 245 (Tex. Crim. App. 1998), the Court of Criminal Appeals addressed whether the trial court properly denied the defendant's requested jury instruction concerning the defense of alibi. In holding that the trial court correctly denied the instruction, the Court of Criminal Appeals noted that alibi "was excluded from the Revised Penal Code's list of defenses and affirmative defenses because it only serves to negate a necessary element of proof in the State's case--the defendant's presence at the time and the location of the commission of the crime. An alibi does not attempt to justify or excuse a defendant's actions." Giesberg, 984 S.W.2d at 248. Defensive issues that merely negate an element of the offense alleged by the State "do not place a burden of proof upon a defendant to establish them." Id. at 250. A defense such as alibi "casts doubt upon whether the State has met its burden" and is therefore "sufficiently embraced in a general charge to the jury that the defendant is presumed innocent until he or she is proven guilty beyond a reasonable doubt." Id. Because a general charge adequately encompasses an alibi defense, "a special instruction for the issue of alibi would needlessly draw a jury's attention to the evidence which raised alibi." Id. Thus, the Court of Criminal Appeals concluded, a specific instruction on an alibi defense "would constitute an unwarranted comment on the weight of the evidence by the trial court." Id. The Texas Court of Criminal Appeals explained why the trial court did not err in refusing to include an "alibi" instruction: "A defensive issue which goes no further than to merely negate an element of the offense alleged by the State in its indictment does not place a burden of proof upon a defendant to establish it. The burden of proof is upon the State to prove those allegations. An alibi only traverses those allegations and casts doubt upon whether the State has met its burden. As a result, an alibi is sufficiently embraced in a general charge to the jury that the defendant is presumed innocent until he or she is proven guilty beyond a reasonable doubt. There is ample room within that instruction for a defendant to effectively argue his defense of alibi to a jury." Id.