Involuntary manslaughter occurs when the defendant has the actus reus (acts and circumstances that have to be proved for the offense to have been committed) of murder but lacks the mens rea (requisite mental state) of murder, but it can be proved that the accused had some lesser form of mens rea related to the victim's death. Prior to the summer of 1993 it was generally accepted that there were two forms of involuntary manslaughter: constructive manslaughter and Caldwell reckless manslaughter. Constructive manslaughter occurs when the accused has the actus reus of murder and causes the death of the victim while perpetrating another crime. The relevant mens rea for this type of manslaughter is the mens rea for the lesser offense that led to the death. Caldwell reckless manslaughter occurs when the accused has the actus reus of murder and has the mens rea to either see the risk to the victim or where the risk is obvious but the accused gives no thought to it. These two forms of involuntary manslaughter must be reconsidered in the context of the House of Lords decision in R v. Adomako, which approved the Court of Appeal's judgment in the case of R v. Prentice. In these decisions the Caldwell reckless manslaughter does not exist; instead there is gross negligence manslaughter; in order for liability for gross negligence to occur, there must be the actus reus of murder, a risk of death, a duty of care, and a grossly negligent breach of that duty. This article considers first the concept of a "duty," as the author argues that its meaning can only be found by considering the concept in the civil law of negligence. Secondly, the element of "gross negligence" is also examined, and it is shown that this is not a purely objective criteria but can also include subjective states of mind, and that the failure to define gross negligence makes it potentially much wider than Caldwell recklessness. The issue of subjective reckless manslaughter is considered, and it is suggested that no such form of involuntary manslaughter currently exists. Consideration is given to reform proposals, and the author argues that constructive manslaughter and gross negligence manslaughter should both be abolished and replaced by subjective reckless manslaughter. 41 footnotes