District of Columbia Code Division VIII. General Laws. § 50-1904.01. Preliminary breath test.

(a) When a law enforcement officer has reasonable grounds to believe that a person was operating or in physical control of a vehicle within the District while intoxicated or while the person's ability to operate a vehicle is impaired by the consumption of alcohol or a drug or a combination thereof, the law enforcement officer may, without making an arrest or issuing a violation notice, request that the person submit to a preliminary breath test, to be administered by the law enforcement officer, who shall use a device which the Mayor has approved by rule for that purpose.

(b) Before administering the test, the law enforcement officer shall advise the person to be tested that the preliminary breath test is voluntary and that the results of the test will be used to aid in the law enforcement officer's decision whether to arrest the person.

(c) The results of the preliminary breath test shall be used by the law enforcement officer to aid in the decision whether to arrest the person, and the results of the test shall not be used as evidence by the District in any prosecutions and shall not be admissible in any judicial proceeding except in any judicial or other proceeding in which the validity of the arrest or the conduct of the law enforcement officer is an issue.