-There are two ways to taking weapons like the Silverballers, etc. through the White House and bypass the metal detectors. The first method is by going to the other end of the parking lot when you start. Look to the left when you get to the end to see an ICA storage box. Put your custom weapons in it, then go into the White House through the double doors at the front and walk through the metal detectors. Keep in mind that fibre wire, syringes, mines and the detonator will not activate metal detectors. Go to the other end of the lobby to find a guard behind a rope watching some double doors. Go into the door on his left (the toilet) and stand facing the corner furthest away from the door and the toilet. Wait for the museum member or staff to walk in and for the door to shut behind him. Take out a silent weapon (fibre wire or syringe) and use it on him before he opens the door, then take his clothes and hide him as best you can against the corner furthest from the toilet, but closest to the door. Check the map and, if there is an innocent person in the lobby looking in your direction, wait for him to start walking away before opening the door-- or he will see the body and you will be shot. Open the door when you get the chance. While behind the ropes, walk across the width of the lobby and through the door on the other side. Then, go directly to the other end of the next corridor and take the last door on the left. This should lead you outside. When you get the chance to take out the U.S. Marine who patrols here, do so, then hide him behind the big steel block. Take his clothes and gun, then walk back out the front doors. You should beep when going through the scanner, but the guards will not shoot you. Take your weapons out of the storage box from the side of the building and conceal them. When you go back in you should beep, but once again the guards should ignore it as long as you have your M14 at the ready.
-For the second method, do the same as above but, when the Marine is out of the way, do not take his clothes or his gun. Work your way back out the front doors and go to the storage box. Take out a weapon and hold it so you can throw it. Aim up and past the fence, towards the White House wall, and bounce your weapon off the wall so it lands on the other side of the fence. Do this with all your weapons and go back to the area where you incapacitated the Marine. Walk down the alley and pick up your guns then conceal them. Make sure you are far enough behind the wall for the guards out the front not to see you. Note: This method is useful if the game glitches and the Marines shoots at you even when you look like one.