On the night in question, D injected the decedent with her first two doses of cocaine, knowing full well that she planned to continue taking injections that evening until their relatively substantial supply of that drug had been exhausted. After the first two injections, the decedent administered her own including the one which immediately preceded her death. An expert witness called by P testified that each of the injections, including the two given by D, was a contributing cause of her death. D was convicted of criminally negligent homicide. On appeal, D contends that his conviction should be reversed and the indictment against him dismissed on the ground that the evidence introduced at his trial was legally insufficient to support the jury's guilty verdict.