Trivia: Although FBI Agent Robert Ressler claims he coined the term "serial killer" (1972), he and John Douglas (together) are often credited. However, Ernst Gennat, Director of Berlin Criminal Police, used the term "serial killer" as early as 1930 in Germany.
Trivia: There were actually two female special agents (including a former nun!) in the 1920s. After they resigned in 1928, then-Director of the FBI J. Edgar Hoover did not permit female special agents. Hoover's restriction was reversed after his death in May 1972 and three female special agents began training soon thereafter.
