An Antiquated System.

The investigation and punishment of crime had always been considered a state or local function. When President Hoover's attorney general reminded the president's critics that the federal government carried no constitutional responsibility for fighting crime, most Americans not only understood but agreed with him. This was a time when agents of the Department of Justice's Bureau of Investigation (the forerunner of the Federal Bureau of Investigation) were authorized neither to carry weapons nor to make arrests. The use of the nation's taxing power to send some of its more notorious gangsters to prison for income tax evasion was a rare demonstration of the federal government's policing power. That power was concentrated primarily in two departments, postal and treasury, and was closely associated with the federal government's responsibility to resist attempts to misuse the mail, to circumvent Prohibition, and to...