At some point during the week Tobias will find an odd bundle in one of the abandoned buildings in the 6th. Someone (a child, going by the size) seems to have left a complete set of replacement clothes behind - a coat, street clothes, underwear - wrapped neatly around a gun in a plastic bag.

If he pokes around the room more, he might find other small piles of things left behind, but they're much smaller and thus better hidden. There seems to be nobody around.