Within the world of Batman: Arkham Origins Blackgate, there are hidden pieces of evidence scattered around for different detective cases. When you find all of the pieces of evidence for a single detective case, you will unlock various Concept Art images. There is a total of fourteen (14) Detective Cases in Batman: Arkham Origins.
Below is the walkthrough for the Ground Zero Detective Case:
Located in the Cell Blocks, head towards the area with the broken elevator shaft. Jump over the gap on the bottom floor and use your Batclaw to get through the gate. The pliers are in the next room.
Chunk of Curved Metal
Located in the Cell Blocks, drop down the hole and analyze the floor to find the metal bracelet. This is right before you enter the main cell block room with all of the floors.
Located in the Cell Blocks, the Rubble Fragments are found in the main cell blocks area with the five floors. Enter the vent on the bottom floor near the left entrance. As you are crawling, scan the inside of the vent before you exit.