The head of the Ung family, Sem Im Ung, is always called Pa in First They Killed My Father. A high-ranking military official in the Lon Nol government, Pa has many skills that protect his family during the chaos of the Khmer Rouge regime. For Luong, he is a source of strength, security, and knowledge. She treasures their conversations on the balcony of their Phnom Penh apartment, particularly his willingness to answer her many questions. Even after his execution, which Luong imagines in graphic detail, his memory is a profound comfort. In her imagination and dreams, she talks to him and he promises her that she has the skills to survive. 

Pa’s job involved unearthing secrets, so he understands how to hide his identity and protect his family. By manipulating his body language, for example, he presents himself as frightened and unthreatening. He knows that the Khmer Rouge seek to destroy things and that their promises are lies. Pa sees clearly that the family’s former lives present a danger, so he insists they keep a distance from past acquaintances and pretend to be peasants. From befriending chiefs to bribing officials, Pa works tirelessly to secure his family’s future. When he knows that he will be executed, he tells Ma the family should scatter. After his death, she realizes how right he was, and sends Luong, Kim, and Chou away.