Definition
A "material witness" is someone whose testimony is crucial to a legal case because they have information that could significantly affect the outcome. They're not necessarily involved in the crime itself, but what they know is vital. Think of them as key players in solving a mystery, even if they weren't directly part of it. The information they possess is essential for justice. They may be compelled to testify, even if they don't want to. It is vital they are available for the trial.