Fiction in which torture doesn't work (open spoilers likely)

I remember that story. They have a little bit of success at the start because they deliberately hire people who empathize with the victims and don’t really want to do it…when they put out the ad for people to apply, they announce to the gathered crowd that they are going to start their training by torturing an animal, and the few people who leave in disgust are the ones they recruit. Over time the torturers stop caring and the torture is less effective, and by the end they are using torturers to prevent hung juries.

Yep - that’s the one. Rather creepy story really.