Would an arrest affect my green card application?

As strange as it may seem, there are some dismissals of criminal cases that can be treated as "convictions" by the USCIS, and there are some offenses clearly identified in statutes as misdemeanors that can be treated as felonies by the USCIS. Some processes by which a criminal case can be dismissed include types of pretrial diversion where the accused is required to formally acknowledge the elements of the offense. In an immigration application process, an applicant must provide court-certified disposition documents for criminal arrests so that, among other things, the USCIS adjudicating officer can determine whether such an acknowledgement took place. If you had been represented by an immigration attorney in preparing and filing the application, that attorney would have reviewed the disposition documents and then would have been able to advise you about this issue, including advising of any steps that might be taken following that dismissal and before filing your application. Additionally, if you were represented by a criminal defense attorney in connection with your arrest, that attorney could have advised you about potential steps to circumvent immigration ramifications. At this late stage, it still may be wise for you to engage an immigration attorney who could review the disposition documents and address the complex issues of immigration-related consequences of criminal matters.