I’ve been a permanent resident since 2003.
I was arrested in 2009 for possession of Class B substance (Felony) - very small quantity, which was in a hotel room that was on my name, police was called due to noise complaint (8 people partying), they entered as the door was open, etc... The case was dismissed with 6 un-supervised, un-restricted pre-trial probation, which as my immigr & crim atty explained to me was as good as Not Guilty.
I want to apply for citizenship myself (without getting an attorney, have financial strains) and my question: Since I was not convicted of anything, did not plea bargain, can this still be the reason to deny me citizenship?
At this point I just want to explain all details (that are not shown in the case, official court copy, etc) to my citizenship/immigr officer at the interview and show her some facts not in the case proving I was completely innocent and I did not accept any plea bargains that’s why I accepted dismissal w/ pre-trial probation (of 6 months expired in 2010).
I have already decided I was going to do it and I am doing this all alone, due to some financial problems, divorce, etc... So I'd be just grateful if anyone could tell me the following:
Since Class B possession = Moral turptitude issue.
1. Is there at least 50/50 chance of getting citizenship?
2. What is the worst thing that can happen to me?
3. Does it matter at all that I was not convicted of anything?
Appreciate your help!

