Iranian judges treat “confessions” as the “proof of proofs,” the “mother of proofs” and the “best evidence of guilt.” The use of forced confessions began in the last years of the shah’s rule, in the 1970s, but drastically increased after the Iranian revolution in 1979. Ayatollah Ruhollah Khomeini regarded them as the highest proof of guilt.

I analyzed numerous legal cases and around 300 prison memoirs for a book about forced confessions. To obtain such “confessions,” interrogators in Iran rely heavily on psychological and physical pressures. They — like fellow interrogators elsewhere — scrupulously avoid the word torture (“shekanjeh” in Persian). In fact, the Iranian Constitution explicitly outlaws shekanjeh. Instead, interrogators describe what they do as “ta’zir” (punishment). Innumerable prison memoirs detail this process. It can be described as Iran’s version of “enhanced interrogation.”

Prisoners are asked a question, and if their answer is unsatisfactory, they are sentenced to a specific number of lashings on the ground that they had lied. These whippings can continue until the desired answer is given — and committed to paper. According to a letter circulated by some 40 members of Parliament, hallucinatory drugs now supplement these traditional methods.

In the 1980s and the 1990s, detainees were routinely shown on television reading their confessions, but the broadcasts were mostly stopped after most Iranians concluded that they were staged. The confessions continue to be used in court, however.

Detainees have a limited number of options in the face of interrogation. They can submit, even before the instruments of enhanced interrogation are displayed. They can undergo prolonged agony, which may lead to death, if inadvertently — interrogators want a confession, not a badly damaged corpse, which can cause political embarrassment. The detainees can accept a plea bargain and “admit” to a lesser transgression in return for release or a lighter sentence.

After the disputed presidential elections in 2009 in which the right-wing populist Mahmoud Ahmadinejad prevailed over reformist opponents, many — including visitors from abroad — gave “exclusive” interviews to the regime press confessing to sundry transgressions, especially helping foreign powers conspiring to bring about “regime change.”