The Questionarie on the CPU is done on the day of medical there's a few computers by the reception desk that you sit at log in to and answers the questions regarding health/mental issues. The investigation is done by MTA they may or may not call your previous employers. The fingerprint investigation is sent to the FBI for verification regarding your eligibity to work and your criminal background, so that's why you must be honest when filling out the initial paperwork for the preintrrview and the 21 page booklet. Your investigation won't come back for a few weeks and of it come who you lied and you are in training they will pull you right out of class and terminate you right on the spot for falsifying official records.