Torture was never really effective. It was quite often used as a method for interrogation, but if you torture somebody enough they'll tell anything you want them to tell you and that isn't necessarily the truth, and as such torture has already been the cause of many miscarriages of justice.
Now I have spoken with people who had the dubious honor to see a prison cell on the inside. I've also spoken with people who work in prison. And then you will find out that there is more to crime than just being disobedient to the law. Some people were driven into crime by events most people can scarcely imagine. Quite often they don't need punishment, but rather professional help and horrible things happened because the help came too late. Some research I did about Bonnie and Clyde indicated that Clyde was actually not really a bad man, but a man who got in jail for a relatively small crime was terribly mistreated in prison (and some say that he was even raped in there) and that he came out pretty paranoid, this in combination with being accused of a murder (and guaranteed the electric chair) he did not commit was the start of the violent journey Clyde made together with Bonnie (and a few more people) in which fear for death row forced them to be violent and always being on the run. This is maybe the most famous story, but one out of many showing that cruel or harsh punishment may satisfy our own desire for judgment, but in the end work counterproductive.
Torturing is a form of mistreatment, and mistreatment leads to paranoia, and paranoia leads to extreme aggression, so basically, torture is not only inhumane, but you are also creating what you desire to destroy. Me being traumatized myself know all too well what mistreatment can cause to a person.
I am not saying that crime should go unpunished. Who does bad things (although "bad" is a debatable word) should pay the price, don't get me wrong, but punishment should lead to realizing that you did something wrong and get you to better yourself. Torture has only led to the opposite.
Now a wise person said: "How you treat your enemies says something about you"
Yeah, punishing evil with evil is technically still evil.