For a copy of a police report in DC here is what you need to do (Taken from the Metropolitan Police website):
http://mpdc.dc.gov/serv/reports/reports.shtm
Police Reports
The Criminal Records Section (Criminal Justice Information Division) provides police reports and clearances for a small fee. Police reports are $3 each (no charge for complainants, their spouses, and parents/guardians). Police clearances are $7. Individuals must request this information in person or by traditional mail. Money orders are required for police clearances and all requests by mail, and are preferred for police reports. For details on obtaining these documents, use the links below:
Criminal Records Section (Criminal Justice Information Division) provides copies of Accident (PD-10s) and Incident Reports (PD-251s). Offense Reports are not made available to the public. However, you may request a related Incident Report for any Offense Report filed with the Metropolitan Police Department.
When an officer arrives on the scene for an automobile accident or for a simple assault, he/she will write an Accident Report (PD-10) or an Incident Report (PD-251). This report is given a six-digit identifying number. Please make a note of this number for future reference. (If you need to find out the report number, call the station of the police district that responded to the incident.) Copies of the PD-10 are usually given to insurance companies for claim purposes.
Effective February 3, 2003, the Criminal Records Section, as well as district stations, will provide copies of Incident Reports (PD-251s) free of charge at the request of the complainant, the complainant's spouse, or the parent or guardian of a juvenile complainant. The requester must appear in person and provide valid photo identification.
Persons living outside of the District, or who are otherwise unable to come to the office in person, may do the following:
Write a letter requesting your police clearance to:
Criminal Justice Information Division
300 Indiana Avenue NW, Room 3055
Washington, DC 20001
The letter must include the following information:
Full Name
Date of Accident or Incident
Location of Accident or Incident
Six Digit Report Number (CCN)
Time of Accident or Incident
Letter must be notarized by a Notary Public prior to mailing
Letter must include a $3 money order (no checks accepted) payable to: DC Treasurer
Include a self-addressed, stamped envelope along with your letter
Please allow six weeks for processing from the date the report is made.
For more information or additional assistance contact (202) 727-8539.
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Since the US Attorney's Office does all the prosecutions in DC, you can also get a copy of the prosecution from them and most likely a copy of the trial transcript from the DC Superior Court.
