A jury is permitted to consider a variety of factors when determining whether a defendant will pose a continuing threat to society. These factors include, but are not limited to: (1) the circumstances of the capital offense, including the defendant's state of mind and whether he was working alone or with other parties; (2) the calculated nature of the defendant's acts; (3) the forethought and deliberateness exhibited by the crime's execution; (4) the existence of a prior criminal record, and the severity of the prior crimes; (5) the defendant's age and personal circumstances at the time of the offense; (6) whether the defendant was acting under duress or the domination of another at the time of the offense; (7) psychiatric evidence; and (8) character evidence. Keeton, 724 S.W.2d at 61. See Keeton v. State, 724 S.W.2d 58, 61 (Tex. Crim. App. 1987). Although the Keeton factors are relevant, the circumstances of the offense "can be among the most revealing evidence of future dangerousness and alone may be sufficient to support an affirmative answer to that special issue." Wilson v. State, 7 S.W.3d 136, 142 (Tex. Crim. App. 1999) (citing Bell v. State, 938 S.W.2d 35, 41 (Tex. Crim. App. 1996), cert. denied, 522 U.S. 827, 139 L. Ed. 2d 46, 118 S. Ct. 90 (1997)).