You have been told already that if you go back you will be charged with trespass. The possibility of them identifying you may be low, however, you do run a risk. Bear in mind if you make any payment via credit card, or any thing with your identification, their system may alert them.Ask a similar question
Why tempt fate? You should stay away from the store. However,, the fact that you are walking around with a false SSN and asking about how hard it might be to detect you tell me that you have some larger issues you may need to address.Ask a similar question
As stated before do not return to Macy's if you were told not to do so. If you come in contact with law enforcement and they have a reason to look into you background, it could land you in trouble. For example, if someone else chooses to shoplift that day and you are a witness or in the vicinity of trouble and police are called, they may look at your record as well. It is not worth risking a violation.
This answer does not constitute legal advice and does not create an attorney-client relationship.Ask a similar question