In Conrad v. Commonwealth, 31 Va. App. 113, 120, 521 S.E.2d 321, 325 (1999) the evidence supported an involuntary manslaughter conviction where Conrad had been awake for twenty-two hours without sleep and chose to drive his vehicle after dozing off several times, before he struck and killed a jogger by driving off the road. Conrad, 31 Va. App. at 124, 521 S.E.2d at 327. Even though Conrad dozed off four or five times but "snapped out of it," he continued driving knowing that he had been falling asleep. The Court upheld the trial court's holding that Conrad should have known because he had dozed off four or five times, that his driving abilities were affected and, therefore, should have known of the risks to human life that his driving created. Id. His decision to continue driving in such a condition constituted "a callous act of indifference to the safety of others." Id. We held that the evidence supported a finding of criminal negligence and upheld Conrad's involuntary manslaughter conviction. Id.