This case file is in Langston's room at Containment Sector.
Traffic Light Procedures
You'll get the case file after taking care of the traffic light in the "Langston's Runaways" mission.
It's in the Panopticon, 4th floor. Same place as the TV.
Typewritten Page Procedures
This is in a hidden area on the 5th floor of the Panopticon (P6 floor level).
In the center of the Panopticon, look to the west. You will see an opening you can Levitate to.
Inside the corridor is the document on the floor.
Water Cooler Procedures
This case file is at the Pump Station at the Maintenance Sector.