[5][6] Nassiri was a classmate of then-Crown Prince Mohammad Reza Pahlavi,[citation needed] which in turn played an important role in his career.

Nassiri was appointed head of SAVAK following the failure of General Hassan Pakravan, the previous director, to prevent the assassination of Prime Minister Hassan-Ali Mansur on 21 January 1965.

The Shah was concerned about the growing authority of the left-wing forces in the country, represented by the extremist and terrorist organizations “Mujahedin-e Khalq” and “Fadaiyan-e-Khalq”.

That is why the shah needed a new leader of the political police who had left the military environment and was well aware of what measures should be taken to protect the throne from usurping power from the army”.

[16][17] Mohammed Reza Pahlavi gave General Nassiri tough instructions - to restore the effectiveness of the SAVAK secret police and to properly serve the monarch.

[18] General Nematollah Nassiri ideally coped with the task set before him by the shah: in the shortest possible time, a rather complex and comprehensive system of total investigation and denunciation was created, which controlled all aspects of the political and public life of Iran.

At the same time, in 1968, Nematollah Nassiri showed interest in establishing contacts with the USSR through the channels of special services, in particular in the acquisition of “counter-intelligence equipment” in the Soviet Union.

He was tried in a Revolutionary Tribunal along with 24 other individuals for a total of 10 hours and was charged – without any defence or concrete evidence of guilt – with corruption on earth, massacre of people, torture, and treason.