The main purposes of criminal law are to protect individuals and their property from harm, preserve order in society, and punish those who deserve punishment. When studying criminal law it is usual to study offences according to the type of harm caused. The main categories are offences against the person, offences against property, and offences against public order. One of the most important ways of classifying offences is by the categories that affect where and how a case will be tried. For this purpose offences are classified as indictable only offences, which must be tried on indictment at the Crown Court. Triable either way offences which can be tried either on indictment at the Crown Court or summarily at the magistrate's court. Summary offences which can only be tried at the magistrate's court. Article 6(2) states that: Everyone charged with a criminal offence shall be presumed innocent until proven guilty. This places the burden of proof on the prosecution.