dr. sonnier's lab, and she was concerned that dr. sonnier had not shown up. >> reporter: dr. joe sonnier was chief pathologist at covenant hospital. >> we rang the doorbell and couldn't get anyone to answer. i certainly don't know his work schedule, but i know him as a person. he would not be late. >> reporter: a lot of people knew dr. sonnier, liked him, too. his sister missy bartlett grew up admiring her big brother. >> he didn't go anything. anything that he pursued, he did it well. >> reporter: philip preswood was a family friend whom joe sonnier treated like a son. >> went through med school, dirt poor, roach-filled apartment, had no money until later in life when he was a successful doctor. he was totally self-made and had that drive. >> reporter: that drive led to a successful career and a marriage that brought him a beautiful family. everything was on track. then in 2001, he suffered a huge setback. his wife left him for another man. his oldest son, dallas. >> so he found himself in his late 40s a single man with his three sons off to college and starting their adult live