Marking the 70th anniversary of one of Japan's most compelling mass murder cases, a Tokyo gallery is showcasing 21 paintings made by a death row inmate who was convicted of the Teigin Incident, with the aim of providing the public with a look into the creativity of the award-winning artist who remained true to his craft even in prison while pursuing exoneration.

Sadamichi Hirasawa was accused of killing 12 people with poison and stealing money from a Tokyo branch of Teikoku Ginko (Imperial Bank), which was known as Teigin, on Jan. 26, 1948.

After first confessing to the murders, Hirasawa backtracked at the start of his trial, maintaining his innocence until he died in prison in 1987, at age 95, after nearly 40 years of incarceration.