D.C. Code § 4-210.10
The hearing officer shall conduct the hearing in such a manner as to insure that both the claimant and the Mayor's agent have the opportunity to present all facts which in their judgment have a bearing on the hearing, and have adequate opportunity to examine material that will be introduced as evidence. He or she shall cause the pertinent proceedings to be recorded. He or she shall allow the individual, or his or her counsel, to examine and cross-examine and to present oral argument and documentary evidence. He or she shall permit the Mayor to introduce such evidence from the case record or other data secured by special investigation as pertains to the case, providing that such data is also made available to the claimant or his or her representative. If data from a special investigation is used, the claimant or his or her representative shall have the opportunity to examine the Mayor's agent's investigator who performed such investigation and to inspect and use for the purpose of cross-examination any data, document, or record secured by the Mayor's agents having any bearing on the matter involved or in the decision giving rise to the hearing. If data from the case record is used, the claimant, or his or her representative, shall be allowed to inspect the case record for the purpose of discovering information favorable to the claimant's case. The Mayor's agents shall not be represented by an attorney at any hearing or administrative review in which the claimant is not represented by an attorney.
D.C. Code § 4-210.10