Question about Immigration Raid on a business

I would think the employer would have that documentation in their possession (as part of the hiring process) and if they can't produce it, then the person may be taken in? Not entirely sure.  I know that even when DS was hired (and he was born here), he had to provide certain documents.  I don't know whether the employer photocopied those documents or not.

if you are legal permanent resident, i believe you are required to have your green card on you at all times. as a US citizen, i guess a copy of your passport, passport card, or BC would suffice.

Until I became a US citizen I certainly did carry proof of legal residency everywhere I went. I never even ran to the store without identification on me. I am always amazed how many people leave their homes without identification on them. I still don't.

I would imagine that by the time it reached the point of an organized raid the authorities pretty much had everyone already vetted. They probably knew who was who before they ever went in there.

In the US, when taking a job, your employer is supposed to take documents from 2 or 3 different lists of acceptable documents. You can see the three lists here: www.uscis.gov/i-9-central/acceptable-documents. The employer should make copies and keep in their HR files on EVERY EMPLOYEE. The employee does not have to carry the documents daily. 

Businesses are subject to being audited for compliance.  If audited, failure to have all documents in order will then cause a raid on your business.  Those with all the required documents in your files will be left alone. Those with incomplete employment files or what appears to be fraudulent files are subject to being picked up. Even then there is normally a detention period while a brief investigation is done.  Who they will contact depends on what you say is your right to work or your right to enter the US.  For example, if someone enters the US on a student visa the ICE agents will contact that school to determine if you are still a full time student with a valid I-20 or if it has been terminated. They aren't going to ask the student to provide that, they contact the immigration office of the school. If the student is in good standing with us as a school and with the SEVIS program they likely will let the student go with a warning about working off campus. Or if we transferred the student to another school we will tell them where the next school was so ICE can contact them.  But if we tell ICE the student's documents were terminated the former student will be deported.  I am not sure who they talk to for other types of visas but every visa has a paper trail that follows it. 

To be hired you must show an original SS card not a copy. To get a SS number you have to be lawfully here in the US. So if your boss did not follow the law and hired you without seeing and copying your SS car, then you are liable to be deported.

In Japan I did at all times. It was a card that said I was legal and could work. I am not sure it had my visa status on it. All Gaijin had to carry them.