Certain accessories-before-the-fact offenses would not be considered criminal under monetary fines, yet it is necessary that such activities be curtailed when prison penalties are used to deter crime. Economic equations can be developed using the monetary time value of imprisonment to show the optimal deterrent value for sanctions relative to the crime agent (surrogate) and the crime solicitor. Accessories after the fact refer to those persons who receive, comfort, or assist criminals. Included under such activities would be any action that reduces the expected magnitude of the punishment imposed on the criminal. If a person helped an offender avoid paying a fine, for example, assigning liability to that person for the unpaid portion of the fine or any additional capture costs due to harboring the offender causes no efficiency problems, because the price for such evasion services would reflect the fine borne by the accessory. When punishment is exacted in terms of imprisonment, however, the optimal penalty for an accessory after the fact changes. In the case of assisting in an escape, the accessory should receive a sanction proportional to the severity of the escapee's original crime. Mathematical equations and 25 footnotes are provided.