D.C. Code § 40-307.02: Enforcement by sale.

If the amount due and for which a lien is given by § 40-307.01 is not paid after the end of a month after the same is due, and the property bound by said lien does not exceed the sum of $50, then the party entitled to such lien, after demand of payment upon the debtor, if he be within the District, may proceed to sell the property so subject to lien at the public auction, after giving notice once a week for 3 successive weeks in some daily newspaper published in the District, and the proceeds of such sale shall be applied, first, to the expenses of such sales and the discharge of such lien, and the remainder, if any, shall be paid over to the owner of the property.