Mens rea is not applicable when it comes to manslaughter.
According to the penal code, “Any person who by an unlawful act or omission causes the death of another person is guilty of the felony termed manslaughter.”
“An unlawful omission is an omission amounting to culpable negligence to discharge a duty tending to the preservation of life or health, whether such omission is or is not accompanied by an intention to cause death or bodily harm.”
This section “…whether such omission is or is not accompanied by an intention…” rule outs the application of mens rea because the section covers unintentional crimes.
Mens rea comes in malice aforethought because malice aforethought is considered intentional and therefore, mens rea can be used to prove that the offence was not premeditated or it was premeditated.