Hitman: Absolution - Rosewood

Orphanage Halls

This evidence will be in the room just before the maintanence area with the fuse boxes. That room is a reception room with several thugs. You will need a disguise to get this piece of evidence.

Central Heating

When you get to central heating, you'll pass a couple of men in the first room and then enter a hallway. Eventually, you'll bump into two more guards in the middle of the hall. By where they are talking is a pile of sheet rock and the evidence is on that pile.