[Qonok]

If it is your first time playing through the game then it will bring the DLC cases up as you go since you will go through each desk during the story.

If you have already played through and are just wanting to do the DLC then load up the desks from the opening screen.

The 'desks' are the various police divisions you will go through like Homicide and Arson. So if you are in Homicide then you are at the Homicide desk.