Judiciary in Iran is chronically corrupted, so the judges. The necessity of being Judge is to be fair and impartial. These are missing qualities in judges in Iran. There are many reasons for that but one of them is in their oath. Let's for once read "oath of judge" in Iran:
In the name of God, the Merciful, the CompassionateAs it is crystal clear in above oath, the obligation of the judge in Islamic Iran would be "strengthening the foundations of the Islamic Republic and supporting The Leader". This judge is dependent to Islamic establishment, he is influenced by establishment and he is affiliation is Islam and The Leader, not independent view.
I, as a judge, in the presence of the Holy Qur'an and before Iranian nation, swear to omnipotent God to follow the Prophet of Islam and the sacred Imams, peace be upon them, and seeking help of the spirits of the martyrs of Islam, guard justice and righteous, and undertake upon my human dignity to be diligent in seeking the truth and justice, administer Islamic justice to demand from oppressor and restore it to its owner and with sustained effort in Judicial position fulfill my obligation to Islamic republic with strengthening the foundations of the Islamic republic and supporting The Leader.
Name and surname
From my point of view, a judge has only one obligation and that is justice.
Oath of judges in Iran in Persian language