The author of Kintomo's assassination was suspected to be Shinbei TANAKA of Satsuma Domain, one of the Bakumatsu Shidai Hitokiri (Four famous assassins of the end of the Edo period), from the material evidence such as the sword left at the scene, and Tanaka was arrested, however, the truth remained unrevealed because he committed suicide during the interrogation.
公知の暗殺犯は現場に残されていた刀などの物証から幕末四大人斬りの一人、薩摩藩の田中新兵衛と目され田中が捕らえられたが、取り調べ中に田中が自殺したため、真相は不明。