For those who don't know:
the reason I am sensitive to this issue, is because my father-in-law was tortured by the Communists trying to extract a confession. Not only were they after confessions, but they wanted people to implicated their friends and relatives.
FiL didn't confess, and he didn't implicate anybody. Unfortunately, someone he knew was so terrified of being tortured, that they didn't even get that far and she was implicating everyone she could think of, and telling the interrogators whatever they wanted to hear. This caused a great deal of trouble for at least DOZENS of people, and probably a great many more due to further confessions and implications.
There have already been cases in the USA of false confessions extracted by threats and possibly even physical duress. One famous case was the so-called "Wenatchee Sex Ring". It was a hoax, but some of the railroaded innocent people confessed after being threatened. Those who failed to confess got longer prison terms!
Similar situations happened in the Amirault mass hysteria. Once it became clear that the Amiraults were victims of mass hysteria, and that there wasn't any real evidence, the courts tried to extract confessions with threats. It partially worked. One gave in. But once you confess, you can't retract it.
Another case close to my heart was that of a friend, who was seized in a mass raid by the secret police in Turkey and sent to a military prison, where he was physically and sexually tortured.
The circumstances were basically being in the wrong place at the wrong time. He was staying in a pension where the owner spoke Farsi, which is his own native language; he doesn't speak Turkish. He was just passing through on his way to Vienna. It was the days of a paranoid military dictatorship, and the military police were wondering why so many foreigners were staying at the pension. It was because the owner spoke their language. So, they raided the place, and put everyone they found there in prison.
My friend was eventually handed his confession. He asked for a translation so that he would know what he was confessing to. It was written in Turkish, which he can not read. They refused to translate it. To this day he has no idea what he confessed to.
(His cousin exited Iran via Pakistan. He bribed a border guard, and no problem! He was on his way without incident. Of course, that was a long time ago, before Pakistan destabilized. Now probably rather dangerous!!)