A conviction for involuntary manslaughter requires a showing that defendant’s conduct proximately caused the victim’s death and where there are multiple concurrent causes of death, the jury need only decide whether defendant’s conduct was a substantial factor in causing the death. Appellant, several others, and the victim met at an apartment where they smoked cocaine. At some point, the group and the victim argued and a fight broke out. Appellant and at least one other member of the group beat the victim and defendant held him while he was tied up. To silence the victim who was yelling, appellant put a sock in his mouth. Some point after the victim was tied up, appellant noticed that he was not breathing and everyone left the apartment. The medical examiner, testifying that the victim died from blunt force head injuries, restraint, asphyxiation, and acute cocaine toxicity, stated that it was not appropriate to separate the factors, and that the combination caused the death. Charged with murder, false imprisonment, and misdemeanor offenses, appellant was convicted of involuntary manslaughter. The court rejected his claim that there was insufficient evidence that his conduct was the cause of death. Involuntary manslaughter requires a showing that defendant’s conduct proximately caused the death and when there are concurrent causes, a defendant is criminally responsible if his conduct was a substantial factor contributing to it. Here, there was sufficient evidence that appellant’s conduct was a substantial factor–he repeatedly hit the victim, placed a sock in his mouth, and gave him cocaine. The court also found that CALCRIM No. 580, as used in this case, adequately informed the jury of the criminal-negligence standard applicable to all forms of involuntary manslaughter and the court had no sua sponte duty to include a further instruction on criminal negligence.