However, it is now (since Frey v. Fedoruk in 1950) a matter of constitutional law that courts cannot create new criminal offences. There no longer are common law offences except contempt of court.
To say that all the offences that we have must be created by Parliament in reliance on s. 91(27) is not the whole story.
The courts can create new defences.
It should be open to the courts to find new grounds on which people should not be held liable.
This has had good and bad effects...
Healy's good examples:
1984: creation of the defence of necessity.
1988: SCC said there is such a thing as a defence of entrapment. Entrapment is a claim whereby accused can show there was abuse of process and ask for stay.
Healy's bad example:
1994: Daviault case, defence of extreme intoxication.
Up to the time that this case was decided, intoxication was only a defence to an offence of specific, not general, intent.
Assault was always viewed as an offence of general intent.
From this, it followed that intoxication was not a valid defence.
Trial judge said the degree of intoxication was so extreme as to eliminate responsibility in committing the act. He thereby expanded the intoxication defence based on the extremity of the defendant's intoxication.
In SCC, there was not one word about general intent, and they decided, essentially, that s. 7 gives us a right to acquittal for self-induced states of extreme intoxication.
If you're intoxicated, you are impaired and you can't be responsible for your actions.
Argument underlying this position actually makes sense: it is a principle of fundamental justice that persons should not be convicted of criminal offences if they are in some way blameless for what they have done. It should be open for courts to reinterpret the meaning of innocence in matters of law.
There is also the defence of duress: person acting under the immediate threat of harm.
History of Criminal Law
Common law was an important source of criminal law at the time of Confederation.
Criminal law in various parts of BNA was not the same.
Sir John A. Macdonald wanted criminal law to lie within the jurisdiction of Parliament given the countries magnitude.
He thought that the criminal law could be seen as a unifying institutional structure.
1869, statute passed to consolidate disparate parts of pre-Confederation criminal law.
1892: Parliament enacted Criminal Code.
Over the years it has grown and been revised. Every session of Parliament brings its changes.
The one we have today is untidy and messy. Much of it is anachronistic and dubious on policy grounds. Large parts are unnecessarily complex.
A revamp of the Criminal Code is unlikely to happen in the near future.