Fundamental principles of criminal liability in England and Wales, focusing on both parties to a crime and inchoate offenses like attempt. The first source details the roles of the Crown Prosecution Service (CPS), the defendant, and the victim, distinguishing between a principal offender (who commits the actus reus and possesses the mens rea) and accomplices or secondary parties who aid, abet, counsel, or procure a crime. It further explains concepts like joint enterprise and the requirements for effective withdrawal from an offense. The second source establishes the legal framework for attempt to commit an offence, requiring an act that is more than merely preparatory to the full crime, as defined by case law like R v Gullefer and R v Jones. Crucially, conviction for attempt demands a high threshold of mens rea, specifically the intention to commit the full offense, and liability can still apply even when the crime is factually impossible, as confirmed in R v Shivpuri.