The Armenian assassin of the ex-Ottoman Grand Vizier Talat Pasha, Soghomon Tehlirian was acquitted of murder in his trial. His defence was that he was killing Talat Pasha in retaliation for his crimes in orchestrating the Ottoman Armenian Genocide.
Tehlirian was tried for murder, but was eventually acquitted by the twelve-man jury. His trial was a rather sensationalized event at the time, taking place shortly after the establishment of the Weimar Republic, with Tehlirian being represented by three German defense attorneys, including Dr. Theodor Niemeyer, professor of law at Kiel University. Priest and Armenian Genocide survivor Grigoris Balakian, German activist Johannes Lepsius, and German commander of the Ottoman armed forces during the war General Liman von Sanders were among several of the prominent individuals called as witnesses to the trial.
The trial examined not only Tehlirian’s actions but also Tehlirian's conviction that Talât was the main author of the Armenian deportation and mass killings. The defense attorneys made no attempt to deny the fact that Tehlirian had killed a man, and instead focused on the influence of the Armenian Genocide on Tehlirian's mental state. Tehlirian claimed during the trial that he had been present in Erzincan in 1915 and had been deported along with his family and personally witnessed their murder. When asked by the judge if he felt any sort of guilt, Tehlirian remarked, "I do not consider myself guilty because my conscience is clear…I have killed a man. But I am not a murderer.
However, murder in retaliation for crimes the victim committed is often not considered a legal defence to the act of murder. For example, this 2013 Baltimore case resulted in the sentencing of the killer to 30 years in jail.
Similarly, the Lillehammer affair involves Israeli Mossad agents sent to assassinate a (mistakenly identified) mastermind of the Munich attacks on Israelis. The agents were arrested and convicted by Norwegian authorities.
A final example was the case of Vitaly Kaloyev, who stabbed to death the air traffic controller responsible for the Überlingen mid-air collision in which his family was killed. He was also convicted for murder in that case and sentenced to prison.
What differences in law in that time in Germany led to the acquittal of Soghomon Tehlirian for murder?