Criminal liability is a state in which a person is found guilty of an offence. In order to have criminal liability certain conditions must be satisfied. A person under the age of ten cannot have criminal liability and for most crimes you must have intention to commit the crime or have committed the crime recklessly for a court to hold that you have criminal liability.
In order for a judge or jury to find that a person has criminal liability they must satisfy two elements: the mental element and the physical element. The physical element is the actual act of committing the crime, so for theft it would be the stealing of the item. The mental element is the intention - in theft you must have been acting dishonestly, if you were not, while you may have some difficulty convincing the relevant authorities of this, you are not guilty of theft. Some offences, such as some motoring offences, have done away with the need for the mental element of a crime to be satisfied.
The burden of proof for criminal liability is beyond reasonable doubt. This means that a judge or jury must be sure that the defendant is guilty before they can convict them. This differs from a civil hearing where the burden of proof is on the balance of probability. The reason for the difference in burden is that in a criminal trial the defendant risks loss of liberty and being burdened for life with a criminal record.
No one is guilty of a criminal offence without fault. In addition, one must be a perpetrator or a participant in the commission of the offence, with the exception of the attempt to commit, which is an offence by itself. Since a corporation acts through its officials, it may well be that the directing mind of a corporation is always a participant in the offence committed by the latter. The Criminal Code provides for a number of ways to become involved in the commission of an offence: by actually committing the offence, by aiding and abetting the principal, by engaging oneself with others in a criminal activity with a common intention, by counselling another to commit an offence and by being an accessory after the fact.
Passive acquiescence, or what is called "mere presence", is not enough, unless the passive attitude contributes to the commission of the offence. Such was the case where a large group of strikers engaged in a human barricade to prevent access to a plant. One can also aid or encourage by not getting involved in a situation where one has a legal obligation to do so.
Generally speaking, anyone who knowingly encourages or facilitates the commission of an offence or impedes its prevention is a party to the offence. While one commonly uses the expression "aiding and abetting", the two are different concepts and either of them is sufficient to engage criminal liability. Whether liability for one's action lies through either concept, it must be accomplished "for the ...