Can a defendant attach to a Rule 12(b)(6) motion to show that they do not support plaintiffs claim?

A defendant may attach to a Rule 12(b)(6) motion the documents referred to in the complaint to show that they do not support plaintiffs claim. See Branch v. Tunnell, 14 F.3d 449, 454 (9th Cir.1994) (overruled on other grounds in Galbraith v. County of Santa Clara, 307 F.3d 1119, 1127 (9th Cir.2002)). The court need not accept as true allegations that contradict facts which may be judicially noticed by the court. Mullis v. United States Bank. Ct., 828 F.2d 1385, 1388 (9th Cir.1987), cert. denied, 486 U.S. 1040, 108 S.Ct. 2031, 100 L.Ed.2d 616 (1988).