Looking through some of the previous posts, I'm still not very clear of the possibilities for this case.
Naturalized US Citizen wishes to petition parents
One parent overstayed B2 visa: -- lawful entry 2000 voluntary exit 2009
I have read about doing AOS, but the parent already left many years ago. There were no removal proceedings, or criminal background. I am unclear if there is a ban on the parent. Also, there is no way to prove lawful entry, as the old passport and visa have now been lost.
Is it possible to petition the parent? I have read about waivers, but they seem to indicate the parent must be in the US.
Any ideas? Thanks in advance!