2 Samuel 13:19

Rent her garment. This was probably done immediately. Tamar made no attempt to cover up the shame that had come upon her. She was a virtuous young woman whose conduct was entirely above reproach. As she left the apartment of Amnon she gave vigorous evidence of the deep grief she experienced within (see Esther 4:1; 2 Kings 5:8).

Thus she prevented Amnon from inventing the tale that she had been guilty of misconduct toward him and for this reason had been expelled from his presence. Tamar was evidently entirely sincere, her actions betokening the keen indignation and grief that were hers. Had she kept quiet she might have been considered a party to the crime.