During World War I the force became involved with federal offenses, and much of the force was organized into a special Home Guard. In the postwar period, the department became highly corrupt along with much of the city government; this state lasted until the late 1930s. Two police chiefs did work within a mandate for anti-corruption and reform. August Vollmer laid the ground for future improvements but served for only a single year. James E. Davis served from April 1, 1926 to December 29, 1929 and from August 10, 1933 to November 18, 1938. In his first term he fired almost a fifth of the force for bad conduct, and instituted extended firearms training and also the dragnet system of policing. In his second term Davis instituted a "Red Squad" to attack Communists and their offices.