why is it cold James king used mr nebsitt to kill him with his own gun

It is unclear why James King used Mr. Nebsitt to kill him with his own gun. It is possible that King was mentally disturbed or suicidal, and hired Nebsitt to carry out the act. Another possibility is that King had some kind of personal or financial motive for wanting to be killed, and used Nebsitt as a means to achieve this. Ultimately, without more information, it is difficult to determine the exact reasons for this bizarre and tragic scenario.