I was checking the jail during the Odunia Hare quest review, since she can also end up being arrested during the course of it, but unfortunately all of the cells in Firewatch jail are full. Three cells are occupied with Firewatch IL NPCs, one cell is occupied by NPC from the Out of Order quest and one cell is occupied by Foul Murder NPCs.

So the best we can do here is to just disable Rinar Sandras after the quest is concluded, I guess.