Books like Waiting period by Hubert Selby, Jr.

In this moral tale, a man pulls back from the brink of suicide when his application to buy a gun with which to shoot himself is delayed by an unexpected computer glitch. Forced to wait until the error is cleared, he begins to rethink his position and eventually decides that, instead of violently throwing his life away, he will dedicate his time and effort to disposing of all those he feels deserve to die. Targeting a bureaucrat in the Veterans' Administration to start with, he devises an ingenious method of murdering him without a trace. His plan a terrifying and vengeful success, the man embarks on a joyful killing spree with a renewed zest for living, having found the true purpose of his existence. But whose is the other voice? The one that comments so wisely and so compassionately, and with such evident approval, upon everything the man does?

First publish date: 2002