R v Kennedy [2007]

R v Kennedy [2007] UKHL 38 is a significant House of Lords case on manslaughter in English criminal law, establishing a legal principle that a person who supplies a controlled drug to a fully informed and responsible adult, resulting in the individual's death due to voluntary administration of the drug, cannot be guilty of manslaughter.

Simon Kennedy supplied heroin to Marco Bosque, who voluntarily administered the drug and subsequently died. Kennedy was initially convicted of manslaughter and supplying a Class A drug. However, the House of Lords overturned the conviction, emphasising the distinction between the act of supplying drugs and the subsequent voluntary administration by the recipient.

The Lords clarified that unlawful act manslaughter required the defendant's commission of a crime, significant causation of the deceased's death, and a dangerous act or significant harm. While Kennedy had committed the crime of supplying drugs, the act itself could not be the foundation for unlawful act manslaughter unless it directly caused harm, which, in this context, depended on Bosque's subsequent use of the drugs.

The Crown Prosecution Service argued that Kennedy could be charged with maliciously administering poison under Section 23 of the Offences Against the Person Act 1861. However, the Lords rejected this argument, stating that an informed and voluntary choice, such as Bosque injecting himself, constituted a novus actus interveniens, breaking the chain of causation. Kennedy's actions did not cause Bosque to administer the drug, and therefore, Kennedy was not criminally liable for manslaughter. The Lords also highlighted that Bosque's act of injecting himself was not a criminal offence under the Misuse of Drugs Act, and Kennedy's supply of the drug did not amount to accomplice liability.

In conclusion, the House of Lords quashed Kennedy's conviction for manslaughter, emphasising the legal principle that the supplier is not criminally responsible when a fully informed and responsible adult voluntarily administers a controlled drug, leading to their death.
Back to blog

UOL Case Bank

Upon joining, you become a valuable UOL student and gain instant access to over 2,100 case summaries. UOL Case Bank is constantly expanding. Speed up your revision with us now.

Subscribe Now

Where are our students from?

Yale University
Council of Europe
Baker Mckenzie 
University of Chicago
Columbia University
New York University
University of Michigan 
University College London (UCL)
London School of Economics (LSE)
King’s College London (KCL)
University of London
University of Manchester
University of Zurich
University of York
Brandeis University
University of Exeter
University of Sheffield
Boston University
University of Washington
University of Leeds
University of Law
Royal Holloway, University of London 
Birkbeck, University of London
SOAS, University of London
University of Kent
University of Hull
Queen’s University Belfast
Toronto Metropolitan University
Hong Kong University of Science and Technology
University of Buckingham

  • Criminal Practice

    Diagrams and Charts

    Our carefully designed diagrams and charts will guide you through complex legal issues.

  • Criminal Law

    Clear and Succinct Definitions

    Key concepts are concisely defined to help you understand legal topics quickly.

  • Property Law

    Statutory Provisions

    Statutory provisions are provided side by side with legal concepts to help you swiftly locate the relevant legislation.

  • Public Law

    Case Summaries

    We have summarised important cases for you so that you don't need to read long and boring cases.

  • Evidence

    Rules and Exceptions

    Rules and exceptions are clearly listed so that you know when a rule applies and when it doesn't.

  • Company Law


    Legal terms and key concepts are explained at the beginning of each chapter to help you learn efficiently.

  • Case Law

    Case law is provided side by side with legal concepts so that you know how legal principles and precedents were established.

  • Law Exam Guide

    Law Essay Guide

    You will learn essential law exam skills and essay writing techniques that are not taught in class.

  • Law Exam Guide

    Problem Question Guide

    We will show you how to answer problem questions step by step to achieve first-class results.

  • Conflict of Laws

    Structured Explanations

    Complex legal concepts are broken down into concise and digestible bullet point explanations.

  • Legal System and Method

    Legal Research

    You will learn legal research techniques with our study guide and become a proficient legal researcher.

  • Jurisprudence and Legal Theory


    All essential concepts, principles, and case law are included so that you can answer exam questions quickly.