The stated purpose of Bill 19-777 is to update and clarify definitions and provisions regarding impaired driving offenses; to authorize the Mayor to promulgate regulations regarding the District's impaired driving program; to specify the type of chemical testing and the admissibility of chemical test results; to expand the list of individuals authorized to draw blood; and provide immunity from civil liability for those indivuduals; to provide subpoena authority for medical records in impaired driving cases involving injury or death; to separate out the offenses of fleeing from scene of an accident and driving under the influence of liquor or drugs; to clarify or increase certain mandatory-minimum sentences for alcohol or drug related offenses; to permit plea options for the offense of operating a vehicle while impaired when they have prior convictions; to provide for a per se impaired driving offense for persons operating under a commercial drivers license; to modernize the implied consent provisions; to modify provisions related to boating while intoxicated; and to make other confirming amendments.