as they had done with c-styles, michelle and monica now tried to find derek. >> i didn't know derek's name. i thought his name was myers. >> and i was spelling derek the wrong way. and looking for him, like, i mean, just forever. >> reporter: if they had managed to tail derek they would have found a guy who didn't seem to fit the profile of a killer. he was doing well, says his sister danielle. >> he had gotten his bachelor's degree in business, he had went on to start his own company. he was doing great. he was always happy, he was always in good spirits, he was driven. >> reporter: he still had that silver mustang convertible with the custom plates "my whip." although monica and michelle never spotted the car, tia did. >> i stopped at a light, and derek pulled up next to me in a car with the top down, listening to music. i just felt like this was so unfair that it's a nice, sunny day, and he's going on with life. it just, like, tripped me out. like, this guy really just did