One of the potential motives behind the killing of 31-year-old Thiwaphan Pao-in was his conflict with a doctor customer over the sale and car-ownership transfer involving a Bt3-million Bentley car early last month. The other motive stemmed from a group of Nakhon Pathom-based people pawning cars to borrow Bt8 million from Thiwaphan, which they failed to repay. Thiwaphan had reportedly made efforts to recover the debt, resulting in arguments.