The two most important criteria in determining a person's domicile are where the person lives and where the person is registered to vote. Place a "P" in the box and show the dates of residence in Maryland.Proof of domicile may consist of two types of evidence: subjective and objective. Yes, you may need to file two state income tax returns. First, you need to determine which state is your resident state. An Affidavit of Domicile is a legal document that serves as a sworn statement used to establish the residence or domicile of a deceased person. We have outlined a few considerations to keep in mind for those looking to change domicile, with a specific focus on moving in or out of the state of Maryland.