In Tibbs v. Commonwealth, 31 Va. App. 687, 525 S.E.2d 579 (2000), the Court held that to support a capital murder conviction under Code 18.2-31(4), the Commonwealth was not required to prove the robbery was a motivating factor for the homicide that was committed. See id. at 705, 525 S.E.2d at 587-88. Rather, a conviction for capital murder will be sustained on appeal where "sufficient evidence is presented from which the fact finder can conclude that the killing and robbery were 'interdependent objects of a common criminal design.'" Id. at 706, 525 S.E.2d at 588.