大津案是一件發生於明治時期之行刺失敗事件。就在日俄戰爭前的十三年，當時還是俄國皇太子的尼古拉二世在訪問日本之際，居然遇到一位名為津田三藏的日本巡警意圖在鄰近琵琶湖的大津市對其行刺。面對著俄羅斯帝國，日本政府與人民都非常恐懼會因此遭受報復。當時明治政府中的許多有力政治人士，甚至向法院施壓要讓該刺客以侵犯皇室的大逆罪接受審判並處以死刑。可是由於缺乏相關的法律根據，大審院的兒島惟謙院長拒絕了來自政府的壓力，並堅持該罪犯因襲擊尼古拉皇太子只能被控以謀殺的罪名，他還企圖說服承辦法官要保障司法切勿受到政治的影響。此案因而成為明治憲法下一項有關司法獨立與國家安全的爭論議題。本文正是試著以法律與歷史的觀點來探討此一大津事件以及其審判。

The Otsu case was a failed assassination in the Meiji period. Thirteen years before the Russo-Japanese War, when the Crown Prince of Russia, Nikolai Ⅱ Aleksandrovich Romanov, visited Japan, a Japanese police officer, Tsuda Sanzo, attempted to kill him in Otsu city near Lake Biwa. Facing the Russian Empire, both the Japanese government and people had a great fear of reprisals. Many powerful politicians in the Meiji government even pressed the court to have the assassin with high treason and punish by death. However, because there was no legal basis, the Chief Justice of the Supreme Court of Judicature (Dai-shin Ing), Kojima Korekata, denied the government's pressure and insisted that the criminal should be charged with attempted murder for attacking Prince Nikolai. He also tried to persuade the handling justices to protect the judiciary from political influence. This case became an arguable issue of judicial independence and national security under the Meiji Constitution. This paper intends to study the Otsu incident and the trial from the legal and historical views.