D.C. Code § 2-413
The judgment in any such action shall constitute a complete bar to any action by the claimant by reason of the same subject matter against the employee of the District whose act or omission gave rise to the claim. No suit shall be instituted involving any claim described in § 2-412 unless the claimant shall have first given notice to the District in accordance with § 12-309 and shall have presented to the District in writing a claim for money damages in connection therewith, and the District has had 6 months from the date of such filing within which to make final disposition of such claim. The administrative disposition of a claim by the District shall not be competent evidence of liability or amount of damages in proceedings on any such claim.
D.C. Code § 2-413