Hello. I see that you posted your question on our other site and I responded to that as well. Ignore the 2nd posted question and I will put in for a refund of that question.
One conviction of an aggravated felony is enough to get someone deported from the U.S. If ICE determines that this is an aggravated felony, then he has the following options:
1) Get a full and unconditional governor's or U.S. Presidential pardon.
2) Hire a VERY good criminal attorney to look into the possibility of reopening his criminal case because something was done incorrectly at the criminal level. If the case can be reopened, then the conviction needs to be vacated (set aside) and then he would need an agreement from the prosecutor not to prosecute him again (which they can do). You can try looking for an attorney at http://www.ailalawyer.com/.
3) Convince the majority of the U.S. Congress to change the law or to make a law of special application only for him called a Private Bill.
These options essentially would eliminate the conviction so that Immigration cannot use it against him to deport him. Unfortunately, sealing or expunging the conviction does not work.
4) IF he became a U.S. Lawful Permanent Resident while inside the U.S. AND he has a U.S. Citizen or U.S. Lawful Permanent Resident spouse or son or daughter that would suffer EXTREME HARDSHIP if he is deported, then he MIGHT stand a chance to not be deported and get Residency again.
Please let me know if you have additional questions and please do not forget to rate my service to you (not the state of the law) as that is the only way that I can get credit for my assistance. Even after you rate the service, I can still answer additional questions for you without additional charge. If you do rate me positively, a bonus is always appreciated. If you would like to request me in the future, just go to http://www.justanswer.com/law/expert-guillermosenmartin/. Thank you!