Adam Holt is a deeply unhappy and disturbed boy, evident by the double murders he committed in his house. It is unclear whether Mr. and Mrs. Holt's divorce was in the works before Adam's murders or after, but it is possible that an unhappy home life may have contributed to Adam's psychological issues. Adam is described as being blonde and pudgy, but as Tony he has a mustache and is darkly charismatic. Perhaps Adam is the victim of a deeper psychological problem, like schziophrenia or multiple personality disorder. This would better explain how he could go from someone so charasmatic, charming, and smooth to someone who threatens, intimidates, and kills.
