In two films about the Titanic, Murdoch was portrayed shooting passengers and himself during the sinking; this was based on a number of eyewitness testimonies of a shooting/suicide by an officer during the launching of the last lifeboat. It is possible that Murdoch was the officer.
In general, to append is to join or add on to the end of something. For example, an appendix is a section appended (added to the end) of a document. In computer programming, append is the name of a procedure for concatenating (linked) lists or arrays in some high-level programming languages.
An appendix is an optional part of a paper. Appendices provide additional material to help clarify concepts for your reader. They are included at the end so the material does not detract from the flow of ideas presented in the paper.