“Section 28 of the Criminal Code, which provides that- “28. A person is not criminally responsible for an act or omission if at the time of doing the act or making the omission he is in such a state of mental disease or natural mental infirmity as to deprive him of capacity to understand what he is doing, or of capacity to control his actions, or of capacity to know that he ought not to do the act or make the omission.” (The second paragraph relates to delusions and is not relevant in this case). The words “A person is not criminally responsible” import that he is not guilty of the offence charged and must be acquitted.”