Murder is a universal concept. There are also varying criminal laws that are called murder, but just because these exist, one must not be thrown off track: the

Murder is a universal concept. There are also varying criminal laws that are called murder, but just because these exist, one must not be thrown off track: the moral, pre-legal concept of an act known as murder remains unaffected. 'Extrajudicial killing' is just an apologetic euphemism. An indirect term, since murder is usually considered to be a bad thing.