Interrogation, of course...but interrogation needn't include torture. The FBI knows this.
It used to be routine for many domestic police forces, around the world,to beat suspects...suspects, not someone proven to have committed any criminal act..."beat a confession out of him" isn't just a quaint saying, it was how suspects were "interrogated", and in some places still are.
I knew people who had been beaten by police, on suspicion, then released without charges because they'd done nothing...doesn't build positive attitudes toward law enforcement and the legal system.