To have a conviction for any controlled substance offense is a ground for removal. This is true even if one is a green card holder.
If one is convicted, or admits to having committed a controlled substance offense, s/he
Can be barred from even obtaining a green card.
Even more, a conviction or an admission of a controlled substance offense may make a person ineligible for citizenship for 5 years.
NOTE: Your information may already be in the FBI database. When you were arrested your biometrics were taken and were more than likely forwarded on in accordance with existing policy.
You cannot assume that because the case was dismissed, and your records expunged, that the same would be true for the FBI database. It might be a good idea to request an FBI records check, just so you will know.
Having said that, let me be more specific about your situation. You will be required to answer truthfully on your application for a visa or any other request for immigration relief or benefits. To not be honest can have dire consequences.
Further, once you leave the country you COULD be rendered inadmissible because of that prior arrest. Remember--- the FBI database.
Because you are not a green card holder, perhaps you should consider another job that does not require travel in and out of the country.
In some circumstance, a dismissal would be helpful if it comes to obtaining a waiver to remain in the country or to reenter the country.
Do asked your immigration attorney to discuss these matters with you especially in light of your situation.
Law Offices of J Thomas Smith J.D., Ph.D 11500 Northwest Freeway, Suite 280 Houston, TX 77092 713-LAWYER-2 www.MyImmigrationLawyer.info
There are different diversion statutes and the bottom line is that if you were required to admit to the facts, then it's a conviction.
The above is intended only as general information, and does not constitute legal advice. You must speak with an attorney to discuss your individual case.
Prior counsel is correct regarding the admission of guilt. It would likely go towards a determination you are inadmissible pursuant to INA 212(a)(2)(A)(i)(II). Assuming you have no other convictions for controlled substances, there is a waiver pursuant to INA 212(h) that is available to you if you are unable to persuade DOS or the CBP that you are not inadmissible. You really should have a much clearer recitation of the criminal proceedings as there may be work to be done to clarify the record.