The Department conducted an extensive investigation into the shooting of Michael Brown. Federal authorities reviewed physical, ballistic, forensic, and crime scene evidence; medical reports and autopsy reports, including an independent autopsy performed by the United States Department of Defense Armed Forces Medical Examiner Service ("AFMES"); Wilson's personnel records; audio and video recordings; and internet postings. FBI agents, St. Louis County Police Department ("SLCPD") detectives, and federal prosecutors and prosecutors from the St. Louis County Prosecutor's Office ("county prosecutors") worked cooperatively to both independently and jointly interview more than 100 purported eyewitnesses and other individuals claiming to have relevant information. SLCPD detectives conducted an initial canvass of the area on the day of the shooting. FBI agents then independently canvassed more than 300 residences to locate and interview additional witnesses. Federal and local authorities collected cellular phone data, searched social media sites, and tracked down dozens of leads from community members and dedicated law enforcement email addresses and tip lines in an effort to investigate every possible source of information.