Gilbert Vasquez went to the home of his friend, Abel Rivera, to watch the Tyson-Holyfield fight. Timotheo (D) and his brother, Gilbert, attacked and killed Vasquez. D stabbed the victim six times; his brother shot the man three times. There was evidence that Vasquez had a bad disposition, but he was not armed with a knife or a gun, or anything more dangerous than a can of beer. D was convicted of first-degree murder. D appealed. D contends the stabbing did not cause the victim's death. D claims that his brother, Gilbert, who was doing the shooting caused the death.