[Alhaitham listens to Sherlock's deductions quietly, nodding along as he speaks and checks off the points of data he'd picked up and how he'd made the connections. When laid out like this its easy to see how Sherlock came to the conclusion that he did; Alhaitham would probably do something similar too if he were in Sherlock's position.]

Fontaine's prison system is more robust that most other nations, though that's in part due to their courts and the Iudex that heads them. I'm sure the Duke will be happy to tell you the details if you want to know more.

[As for people being without their Visions... well maybe you should ask Heizou about the Vision Hunt Decree one day, Sherlock.]