I am filling out a N-400 form (application for naturalization). I had an arrest last year, case was sealed after 5 months.

When you go for interview, USCIS will need original documents of your Police Records, disposition and judgment of the court. It's better to send copies of all the records you have with application.

Submit copies of the entire record, including a copy of the court order sealing the arrest or conviction, if one exists. If you haven't already consulted with an experienced immigration lawyer you should do so before submitting the N-400.

It is usually best to have a certified copy of the complete file, prior to having been sealed. If the file was sealed before you got copies, you will need to have it unsealed. Talk to an attorney, in most cases a sealed record isn't really sealed when it comes to CIS and the FBI.

A certified disposition of the criminal charges should be sufficient. I agree with my colleagues. When you have had criminal charges the best practice is to consult with an immigration attorney . Criminal charges can affect your application for naturalization in different ways. Criminal charges may also affect your eligibility to maintain your status as a permanent resident. It is best to know what you are up against before you file, or at least before your interview.

If there was a conviction, you must consult with an attorney before you file to naturalize. Some convictions make you deportable.