jsidhu762: I heard you are able to access that cabinet right after the demons start invading. How do I do that?

TheMonkofDestiny: Not long after everything goes bad, you'll come across a security terminal. If you access it, you can unlock a number of things, including the other side of that cabinet where you originally pick up your pistol. After you use the terminal, it's just a matter of walking back to the cabinets at the security check point and collecting the other gear.

Serpent1989: TheMonkofDestiny has already pointed out everything right. The only additional tip I would like to give to you is to carefully read all the E-Mails in the PDAs that you find, as well as listening to the audio logs in them. When you pick up the PDA of Grant Baston, which can be found in a small open room with another cabinet, close to the worker R. Fry talking to his colleague working in a shaft and just left of the door leading to Convergence Chamber 2, you will find an E-Mail from T. Brooks inside the PDA, in which he boasts how stupid some guys were, that did not knew that you can open both panels via the same security panel, which is kind of a subtle hint. As you need to use that computer later in the game anyway, it shouldn’t be a problem for you to open the second cabinet. Anyway, read all PDAs you’ll find throughout the game (it’s a lot of them!) carefully and listen to the audio logs too, as they contain most of the codes as well, that will help you already very much. Sometimes looking closer at the computer screens is also a good option, as a few of them can even be used and some of these few usuable computers even for your own good. :-)