david's white lexus abandoned in a supermarket parking lot within walking distance of their house. there was no blood or sign of violence in the car, but something immediately caught investigators' attention. >> one of the first things investigators notice is that the seat is pushed up toward the steering wheel, which would indicate that a much smaller person had been in it last and not a big man like david nixon. >> investigators hope the store's security cameras might shed some light on who left david's car in the lot.