The purpose of this research is to investigate the follow-up of Iran's complaint against Israel in international authorities regarding the assassination of nuclear scientist Shahid Fakhrizadeh, which is done in a descriptive-analytical way. During the years 2008 to 2019, six scientists related to Iran's nuclear technology were targeted by organized terrorist attacks by human rights violators, despite the prohibition and condemnation of these attacks according to Article 6 of the International Covenant on Civil and Political Rights approved in 1966. The United Nations and by human societies, in the opinion of "Mother Dagan", the former head of the Mossad, it is much more ethical and efficient than creating a large-scale war, according to Dagan's belief, in the territory and sovereignty of Iran, leading to gross violations of human rights and taking the lives of five The target person became the perpetrators and their commanders. Despite these authors, they have studied the method of committing assassinations separately and analyzed them by using the capacities of domestic and international law in order to answer the question of what is the title of assassinations in domestic and international law. They are under criminal titles, and which authority is responsible for dealing with these crimes? And is it acceptable to claim that the behavior is a defense? The results of the research show that considering the passage of two decades since the approval of UN Security Council Resolution 1373 and the lack of criminalization of terrorism in Iran's legal system, each assassination has a different criminal title and punishment, so simply committing it creates the qualification for a special authority. It is not a domestic criminal offense. According to the circumstances of crimes against humanity in the Rome Statute approved in 1998, the behavior is an example of this international crime, which despite Iran not joining the International Criminal Court, this judicial authority can be considered competent to deal with it, also citing Article 51 of the United Nations Charter and Resolution 13314 of the United Nations General Assembly rejects the claim that the behavior is defensive and justifiable in any case.