Can a serial killer recognize one of his own? Kim Byeong Soo (Sol Kyung Gu) is a former serial killer who used to kill people he thought deserved it because of their atrocious actions, starting with his violent and abusive father. After a car accident contributed to the onset of Alzheimer’s disease a decade ago, Byeong Soo stopped killing and now leads a quiet life with his daughter, Eun Hee (Kim Seolhyun). Byeong Soo keeps a secret diary and voice recordings to try to help him retain his fleeting memories. One day, Byeong Soo becomes convinced that Eun Hee’s boyfriend, Tae Joo (Kim Nam Gil), also is a serial killer. Byeong Soo solicits the help of his police buddy, Byeong Man (Oh Dal Soo), to bring Tae Joo to justice. But when Tae Joo abducts Eun Hee, can Byeong Soo save her in time or could the entire event be his own mind playing tricks on him? “Memoir of a Murderer” is a 2017 South Korean film written and directed by Won Shin Yun. It is based on the novel A Murderer's Guide to Memorization by Kim Young Ha.