This is the second part of the Skurky’s Law Mission in Hitman: Absolution which is called the Holding Cells. In it you make your way through the holding cells to get to the entrance of the prison of the courthouse. This guide explains how to complete this mission on the hardest, purist, difficulty. It does not explain how to complete the different challenges in this area.
At the end of this guide is a YouTube video with a visual version of this guide.
This area doesn’t have the score system enabled so killing everyone in it isn’t going to have an impact on your rating. At the start just walk all the way to the entrance of the prison. Make sure you pick up the fire extinguisher in the room outside of the entrance area (the room with the cell door which has the entrance to the prison in it). There you have to wait for the third police officer that shows up in the room outside of the entrance area to have left again and the police officer that walks in and out of the entrance area to be out of it. Then throw the fire extinguisher into the room outside of the entrance area: