I found a key a while back and it said to look out for a lock or a box that the key fits, I assume it's the evidence locker or did I miss a locked box? The optional quest is no longer listed under the objectives so did I miss whatever the key is for?
Once you open another tear, go back up to the second floor. Look in one of the offices for a Brotherhood of the Raven chest, the one that needs the key. There should be a voxophone near it now. Go to the graveyard shift, the little pub in the beginning of Shantytown. Go to the back area of the bar and look down there for the key. Should be in the area behind the orphan boy (not directly under the stairs where he is, there is a little nook you can move in to.)
"I loved throwing cans of flatulance at people sitting in corners. Even the hitmarker noise sounded like a fart. I will also miss those days." -aj4x94