Appellant challenges his convictions and sentences on several grounds. We find that one has merit, and we reverse and remand for a new trial. The trial court failed to conduct a full inquiry and to make the required findings when the state committed a discovery violation by calling a witness not disclosed on their witness list. See Richardson v. State, 246 So.2d 771, 775 (Fla. 1971); Hatcher v. State, 568 So.2d 472, 474 (Fla. 1st DCA 1990), rev. denied, 577 So.2d 1328 (Fla. 1991). We are unable to conclude beyond a reasonable doubt that the discovery violation and the trial court’s failure to conduct a full inquiry did not prejudice the defense. We are, therefore, required to reverse. See State v. Schopp, 653 So.2d 1016, 1020-1021 (Fla. 1995).