You need to interact with two pieces of paper in the Fairfax house to get this.
The first time you arrive you will be stood at the door and have to interact with Mr Fairfax (the priest) to show him your ID.
You'll then move inside. Your partner will be talking to them over by the couch/TV so go down the corridor to the right of them, then into the first open door on the left to find their bedroom. Look to your right as you enter to see a dustbin against the wall next to the bed. Go over and examine the application form in the top of the bin to pick it up.
The next time you come here, when you use the lockpick to enter, go to the kitchen and look at the paperwork on the counter near the microwave - you'll pick up the successful application form and get the achievement.