D.C. Code § 16-503
A creditor may maintain an action and have an attachment against his debtor's property and credits, where his debt is not yet due and payable, if the plaintiff, his agent, or attorney files in the clerk's office, at the commencement of the action, an affidavit, supported by testimony of one or more witnesses, showing the amount and justice of the claim and the time when it will be payable, and also setting forth that the defendant has removed or is removing or intends to remove a material part of his property from the District with the intent or to the effect of defeating just claims against him if only the ordinary process of law is used to obtain judgment against him, and if he also complies with the condition as to filing a bond prescribed by section 16-501. The plaintiff may not have judgment before his claim becomes due. If the attachment is quashed the action shall be dismissed, but without prejudice to a future action.
D.C. Code § 16-503
Nonresident or absent defendants, service by publication, see § 13-336. .