article_snippet: A medical student on trial for stabbing a Georgetown law student to death has used a rare defense - claiming A medical student on trial for stabbing a Georgetown law student to death girlfriend committed second-degree murder, despite A medical student on trial for stabbing a Georgetown law student to death .
article_snippet: Rahul Gupta (right), a medical student on trial for stabbing Mark Waugh,  (left) a Georgetown law student to death has used a rare defense - claiming a Georgetown law student to death committed the murder .