Kim Tae-woo
The autopsy report shows that one North Korean soldier, Jeong Woo-jin (Shin Ha-kyun), was shot eight times repeatedly, indicating a grudge was held; additionally, a single bullet is not accounted for. Over the course of the investigation, witness Private First Class Nam Sung-shik (Kim Tae-woo) attempts suicide by jumping out of the window of the interrogation room and a strange emotional reaction between Kyeong-pil and Soo-hyeok during a meeting causes Sophie to confirm her suspicions that the surviving soldiers and Woo-jin held a mutual friendship and were attempting to protect one another.