Every region and city is different, and I can only speak to Chicago with my answer.

In the early 1900s, it was not uncommon for police to arrest misbehaving children and punish them physically at the police station, rather than bringing them before a judge. In some instances, the parents were called to the police station to observe. In other instances, the beating happened on the street and the child was released.

In the 1920s, it was common knowledge that arrested suspects were beaten by police during interrogation. Some stations kept a closet of rubber hoses and phone books in which to beat the suspect. This was called the "goldfish" treatment.

Another poster could make a valid argument that suspects continue to be tortured. The difference now is that it is considered illegal, which reflects a change in standard.