turns out in the months before julie's death mark meets a new co-worker at his brokerage firm, kelly labontes a professional woman in the office. she was young and good looking and confident. >> kelly labonte worked for the same company but in a different office. in fact, she was based in st. louis while mark was based in racine. >> mark jensen had started working down there, was traveling down there regularly. >> they had begun to instant message. instant messaging was sort of a precursor to texting. it was something that occurred over the internet, but at that time it was sort of fresh and new and exciting. >> the emails between mark and kelly really heated up in intensity in about august, september of 1998. >> and ultimately, he and she hooked up and became an item unbeknownst to julie. >> we pretty much knew right from the very beginning that mark and kelly were in a relationship. >> what made you believe that they were more than just friends? >> what's the old yisaying? nobody knows what goes on behind closed doors. the doors were closed, and they really didn't need to be closed. >> so