## Facts

- Blakely and Sutton, seeking to prevent their friend from driving after drinking, added sugar to his tonic water, believing it would reduce intoxication.
- Unbeknownst to them, the added sugar actually increased the friend’s blood alcohol level.
- The friend proceeded to drive and was subsequently convicted of drunk driving.
- Blakely and Sutton were charged with aiding the offence of drunk driving.

## Issues

1. Whether Blakely and Sutton could be held criminally liable for aiding the offence, despite not directly committing it.
2. Whether their actions constituted causing, assisting, or merely allowing the crime to occur.
3. Whether the friend’s independent choice to drive broke the causal link necessary for establishing liability.

## Decision

- The court determined that Blakely and Sutton did not aid the offence.
- Their conduct, while misguided, did not amount to directly causing or assisting the commission of the crime.
- The friend’s voluntary decision to drive after drinking constituted a separate act (_novus actus interveniens_), severing the chain of causation.
- The defendants retained no control over the friend’s actions; his decision-making remained independent.

## Legal Principles

- Liability for an offence without direct involvement requires a clear, direct link between the defendant's actions and the commission of the crime.
- There is a distinction between causing an offence (requiring direct causation), assisting (helping during the act), and allowing (providing support).
- The existence of a _novus actus interveniens_—a voluntary, independent act by another—can break the chain of causation and absolve indirect participants.
- Courts must establish whether the defendant’s influence actually led to the offence, or if the principal’s independent decision intervened.

## Conclusion

Blakely & Sutton v DPP clarified that indirect participation in a crime does not suffice for aiding liability unless the defendant’s actions directly cause or assist the offence; an independent voluntary act by the principal offender may break the chain of causation, precluding criminal responsibility for indirect participants.


Blakely & Sutton v DPP [1991] RTR 405