 The Investigative Support Unit ("Mindhunters" is slang for the ISU)  is the FBIs special force that has assisted state and local police  in cracking some of the United States most notorious serial murder  cases. Mindhunters specialize in understanding and profiling the  chemistry and mechanical workings of the brain in these serial  criminals. Mindhunters train in a multidisciplinary capacity,  including highly demanding field training and research of such  murderers as Charles Manson (qv) and David Berkowitz (qv) (the  Son of Sam).