D.C. Code § 19-602.27: Set-off.

Without qualifying any other statutory right to set-off or lien and subject to any contractual provision, if a party is indebted to a financial institution, the financial institution has a right to set-off against the account. The amount of the account subject to set-off is the proportion to which the party is, or immediately before death was, beneficially entitled under section 19-602.11 or, in the absence of proof of that proportion, an equal share with all parties.