Head over to the middle of the search area. Nearby where you started the riot, you will find a locked door and beyond is your target. It is in the higher portion of the area so expect to do some climbing and guarded by 2 Soldiers.
Overall, it is very to get to. If you want to head directly there without using any of the opportunities, then head out to the middle of the room. Turn to the North, take out the local Raider Leaders to scatter their forces. Jump across it and then turn to the West and head up the stairs. Kill the Orator to stop him noticing you and scatter the forces below. Head to the Upward stairs in the Western portion of this area.