Although not mentioned in this case, the plaintiff that sued Marshall maintained that he had been negligent in supervising Rojas while she was assigned to the Ryden engagement. That negligence, according to the plaintiff, had contributed to Rojass decision to embezzle funds from Ryden. Briefly describe the supervisory responsibilities that the U.S. auditing standards impose on senior personnel assigned to an audit or accounting services engagement. To what extent does a supervisor on such engagements have a responsibility to prevent his or her subordinates from engaging in criminal activity?