By representing himself in the penalty phase of his trial for the church massacre in Charleston, S.C., Dylann Roof joins a roster of notorious killers who have gone that route — a list that could serve as a caution to anyone considering following their lead.

Some criminal defendants who act as their own lawyers want a stage to promote an ideology; some apparently want the spotlight or think they can fare better than a real lawyer; some are too controlling to let anyone else be in charge; some are too paranoid to trust lawyers; and some are just delusional.

Whatever the motive, it rarely ends well for the defendant. Judges routinely advise against it, and often insist that court-appointed counsel be on hand as a backup.