In Zimmerman v. State, 860 S.W.2d 89 (Tex. Crim. App. 1993), the defendant claimed the evidence was insufficient to prove that he formed the intent to rob the victim before the murder. 860 S.W.2d at 92. The defendant's conviction was based in part on letters written by the defendant from jail. In one letter, the defendant wrote that the victim "had 4 or 5 hundred dolars (sic) on him and we were drinking so I decided to kill him and take his fucking money." Id. Because there was trial testimony that the victim's wallet was not taken until after an altercation in which the victim was stabbed, the defendant argued the evidence was insufficient to prove that his intent to commit the robbery was formed before the murder. The Court held the jury could rationally conclude the defendant had formed the intent prior to the murder, based on the defendant's statement in the letter. Id. at 93.