Nobody should be tortured.
We do have other techniques, such as the "truth serums" (which basically are tranquilizers and anesthetics carefully administered to supress temporarily the critical functioning of the frontal lobe) and hypnosis (when it works), and these are nonviolent, assuming no drug sensitivity and reaction. These are better to use, and the most that we need to use. We do not need to use torture and we should not, even if we do not get the information that we want.
Torture harms the torturer far more than it does the tortured, and it damages the tortured severely. It is not needed. We must not use it. Questioning and imprisonment, even surveillance and drugs are acceptable, but not torture.