Further investigation showed that Zhang had flown from Dalian to Beijing and returned to Dalian on Flight 6136 the same day. According to security camera recordings, he had spent several hours smoking cigarettes in the waiting hall of Beijing airport. Zhang purchased two insurance policies before leaving Dalian and purchased the remaining five in Beijing. Some water bottles filled with gasoline were also found in Zhang's apartment. The investigation also showed that Zhang was married, had a son, ran his own company, and was in a large amount of debt.