The perpetrator was Yigal Amir, a 25-year-old former Hesder student and far-right law student at Bar-Ilan University. Amir had strenuously opposed Rabin’s peace initiative, particularly the signing of the Oslo Accords, because he felt that an Israeli withdrawal from the West Bank would deny Jews their “biblical heritage which they had reclaimed by establishing settlements”. Amir had come to believe that Rabin was a rodef, meaning a “pursuer” who endangered Jewish lives. The concept of din rodef (“law of the pursuer”) is a part of traditional Jewish law. Amir believed he would be justified under din rodef in removing Rabin as a threat to Jews in the territories.[15]
https://en.wikipedia.org/wiki/Assassination_of_Yitzhak_Rabin