the detective took a break, went upstairs to speak with his partner, detective sedlak. >> and it was then i asked him if he minded if i had a shot. i wanted the chance to talk to her myself. >> and so the detective decided to play good cop, bad cop with morgan. >> i want to hear everything. and you better start at the beginning because the game's over. >> and now morgan was about to offer a new piece to the puzzle. a truly shocking one. it had started as a joke, she said, the two lovers imagining kevin out of the picture. >> joking around, we could take kevin out, yeah, right. >> what would happen, they wondered, if they put something in his favorite drink. >> he put nicotine, straight nicotine in a snapple that he bought. >> following a recipe he found online, he put chewing tobacco into a toxic substance called liquid nicotine. he then slipped it into kevin's n snapple. >> who handed the snapple to your husband? >> i did. >> and then what? >> i left and got my kids off to school. >> but morgan insisted she never expected any real harm to come to kevin, never expected steve would ta