Under the law a check is a type of negotiable instrument that allows a person or an entity to transfer money to another person or entity. The issuer, the person writing the check, fills out the "pay to the order of" line with the name of the person who will receive the money. The person whose name is on the check on that line is the owner of the money at the time when the check is cashed.
Once the money is deposited into a bank account the owner or owners of the account have access to the money that is inside the account and may draw on it, take money out. There are many types of bank accounts and each type has their own rules. The bank that holds the account will be able to provide detailed information on how the money in a specific account may be accessed and by whom.
If a person who is not authorized is removing money from your account then they are committing theft under A.R.S. 13-1802. Theft is when a person intentionally takes the property of another, including money, intending to keep it.
Arizona Law states:
13-1802. Theft; classification; definitions
A. A person commits theft if, without lawful authority, the person knowingly:
1. Controls property of another with the intent to deprive the other person of such property;