Your question requires an attorney consultation. It is not a simple question that can be answered on this type of forum. There are many factors that would need to be considered and evaluated. Briefly, if he has his green card, has been a Permanent Resident for at least 5 years (3 years if he received his green card through marriage to a U.S. Citizen), has no criminal conviction and can show good moral conduct for the preceding 5 years, and has not been out of the country for more than 2 years (cumulative) during the preceding 5 years, he would be eligible for citizenship. I suggest that he contact an experienced immigration attorney for a face-to-face consultation and give him/her all of the facts surrounding his situation. He/she would then be in a better position to analyze his case, advise him of his options and make sure that the necessary paperwork and documentation is presented so as not to delay the process.
Answered on Nov 19th, 2012 at 4:42 PM