dead set on destroying the marriage any way she could. >> rob taglianetti she wanted out of her life. reed, she wanted to be with him. she did whatever she needed to do to accomplish both those ends. >> reporter: take rob's discovery of his wife's suggestive email. the defense said mary left the email open on purpose. why? maybe because a confrontation between the two men was her goal. why else, he said, would she not have alerted the authorities to her husband's impending showdown with the superintendent? >> if you're really worried of what you're husband's going to do to another individual, wouldn't you call the officials, wouldn't call the police? she waits literally days to call law enforcement. >> reporter: mary, a prosecution witness, says she's appalled by the defense's theory and finds it preposterous. how was killing keith reed and getting her husband thrown in prison supposed to solve any problems? >> i didn't do anything of that on purpose. >> reporter: did you willingly provoke him, as the attorney suggested, even leaving open the email to -- >> no. no, no. i wished i woul