During a take, when Grissom and Brass are interviewing Marlon Waylord (D.B. Woodside), Woodside flubbed a line and was about to call Grissom "Grisham" but corrected himself midway through the name by saying "Grish-som". The producers decided to keep that take because the way Woodside had said it made it sound more menacing.
A rare instance in this episode, where neither Grissom nor one of the other CSI members initiate the theme with an unique quote or a case-related reference. In this case, it's the victims mother yelling at Grissom that starts the theme.