The FBI Laboratory, established with the formation of the BOI, did not appear in the J. Edgar Hoover Building until its completion in 1974. The lab serves as the primary lab for most DNA, biological, and physical work. Public tours of FBI headquarters ran through the FBI laboratory workspace before the move to the J. Edgar Hoover Building. The services the lab conducts include Chemistry, Combined DNA Index System (CODIS), Computer Analysis and Response, DNA Analysis, Evidence Response, Explosives, Firearms and Tool marks, Forensic Audio, Forensic Video, Image Analysis, Forensic Science Research, Forensic Science Training, Hazardous Materials Response, Investigative and Prospective Graphics, Latent Prints, Materials Analysis, Questioned Documents, Racketeering Records, Special Photographic Analysis, Structural Design, and Trace Evidence. The services of the FBI Laboratory are used by many state, local, and international agencies free of charge. The lab also maintains a second lab at the FBI Academy.