According to Robotnik's propaganda machine, the "luxurious" Highview facility focused more on rehabilitation than punishment, and indeed no inmate had ever re-offended... although this was in fact because they were almost all hanged. In reality, the "Corrective Centre" is little more than a dungeon in which prisoners are chained up on the walls, and the warden is the vindictive Mister Gullets.
After his mock trial, Captain Plunder was locked in Highview for four weeks, waiting to be hanged for robbing Robotnik's Robotnicus airship. All of his appeals were denied. He was chained up by his arms next to Simpson the Cat, but when he learned that Simpson knew a secret way out of the cell he used a mechanical device in his hook to break free.
Plunder and Simpson broke their chains, defeated Mister Gullets, and escaped the prison through a tunnel dug by Billy Gulch. Gulch had spent twenty years digging it, but the day before he was going to use it they pardoned him and the poor guy never used it. Meanwhile Plunder's crew, led by Filch, were coming the other way through the tunnel to rescue him. Plunder and Simpson hid from the crew, not recognizing who they were in the dark. The crew reached the prison, found Plunder had already gone, and were promptly captured, all except for the ghost Filch who escaped by walking through the wall.
Plunder's escape from Highview made (almost) all the headlines the next day.