Regarding the 'caution' for the death threat. There are two different types of police behaviour popularly referred to as cautions or cautioning. One is an informal caution- a warning about the likelihood of future police action should such behaviour occur. This is used where police believe that a crime may have been committed but that it does not meet the level required for prosecution. This sort of caution is a one way affair- the person essentially being 'told off'. The second form of caution isa Formal Caution, issued by a Police Officer of at least Inspector rank who decides that a crime has been committed and that there is sufficient evidence to refer it for prosecution, but that it is not necessarily in the interests of justice to do so. The person is formally informed of the fact that they could be prosecuted and given the option of accepting a caution; this requires the person to formally admit to the crime and becomes part of the criminal record.