Kiyoshi Ōkubo

Kiyoshi Ōkubo (大久保 清, Ōkubo Kiyoshi; January 17, 1935 – January 22, 1976) was a Japanese serial killer. Between March 31, 1971, and May 10, 1971, he raped and murdered eight girls and women. He used a pen name, Tanigawa Ivan (谷川伊凡).

Source: “Kiyoshi Ōkubo”, English Wikipedia (CC BY-SA 4.0), excerpt