How do they know when you left US?

[gameraja]

I have been reading all the posts in this forum and one thing I don't get is How would the POE officer know when you left US. All GC holders don't have I94s anymore that would tell when you left US.
I agree that it is the duty of the PR to tell the truth, but if one were to lie how can they find out when you left US.(Passport stamping in only on the othe side of the border, that can be done with a small visit to Singpore)

Just curious.

PS: I just got a green card and have some idle time to think

 

[rummenigge]

The airlines have to give their passenger manifests, i.e., the list of all passengers, including citizenship, passport #, and legal status in the US, to them. This is nowadays done electronically.

airline knows my passport number? not aware. i passed my passport, they checked name and gave me back. Were they magicians and scanned my passport number without my eye closed?

 

[harvydonald]

Sometimes they don't.
One of my relatives who was on GC took one week trip to Europe, and 13 months later he took another one week trip to Europe.
On his return the office accused him of abandoning his PR by staying out of the country for 13 months. He was sent to secondary inspection.
He was flying on e-ticket so did not have ticket stubs to prove. Luckily he had renewed his Drivers License just weeks before and he had the paper reciept in he wallet. That was proof good enough.