Respuesta :
Answer:
A subpoena
Explanation:
In this case, the only witness refuses to testify, so the prosecution needs something from a legal resource to compel the witness to talk. There are resources used by the police and the prosecution to make it happen, for example, create a case of obstruction of justice, or justify probable cause of the neighbor involvement in the murder (way more complicated than it sounds), yet the easiest one is a subpoena, that is nothing more than a "document" or written order by a government agency or court, to create an obligation of the witness to give testimony or suffer a penalty, of course, there are complications, since the prosecution has to prove that the neighbor is the only key witness and that he/she was on the porch at that day and time, but that's another story.
Hope this helps