She began to insist that her disappeared son was abducted by agents of the North Korean government.
[2] At the time, Chizuko Okamoto lived with her 35-year-old stepson Minehiro Yamauchi and her 19-year-old daughter Rikako.
Yamauchi's mother found the bodies of her son and Rikako in Okamoto's apartment in Hiratsuka, Kanagawa Prefecture on May 1, 2006.
During the trial, Chizuko Okamoto insisted on her innocence and claimed that Minehiro had killed Rikako.
On July 23, 2007, the Yokohama District Court sentenced her to 12 years in prison for the murder of her daughter.