Possibly. It could possibly go under casualty or bad debt depending on the situation and how you documented it.
The Internal Revenue Service defines theft as any crime involving "the taking and removing of money or property with the intent to deprive the owner of it." The definition covers burglary, robbery, embezzlement, extortion and even blackmail. The taking of money through fraud or misrepresentation also counts as theft if the action violates state or local law. Filing a police report helps you document the theft in the event the IRS asks you to substantiate your deduction.
If your situation does not fit the definition of theft above from the IRS, perhaps it could be a bad debt if the person owes you money for your services.
A bona fide debt is one arising from a debtor-creditor relationship based on a valid and enforceable obligation to pay a fixed or determinable amount of money (Regs. Sec. 1.166-1(c)). The taxpayer must be able to show that it was the intent of the parties at the time of the transfer to create a debtor-creditor relationship. In other words, the taxpayer must be able to show that at the time of the transaction, he or she had a real expectation of repayment and there was an intent to enforce the indebtedness.
Generally, a business bad debt is one that comes from operating your trade or business. You can deduct business bad debts on Schedule C
(Form 1040) or your applicable business income tax return
