The Federal Probation Act of 1925 (43 Stat. 1259) authorized district court judges to appoint a salaried officer and unpaid volunteers to investigate and supervise federal "probationers"-those persons who were convicted of a federal crime but whose sentences were suspended pursuant to the terms of that act. The probation officers investigated any case referred to them by the court, furnished each person on probation with a statement of the terms of their suspended sentence, and arrested such persons, without a warrant, for violating those terms. The first appointments were made in 1927, and within four years sixty-two probation officers served in the fifty-four judicial districts.

In 1932 Congress expanded the duties of probation officers to include the supervision not only of probationers but also of parolees and prisoners who were "conditionally released" for good behavior. In 1946 they became responsible for the supervision of military parolees, and in 1947 for monitoring juvenile offenders who qualified for deferred prosecution under the terms of the Federal Juvenile Delinquency Act of 1938. With the passage of the Federal Youth Corrections Act in 1950, probation officers acquired a number of responsibilities relating to offenders between the ages of eighteen and twenty-two who were eligible for a flexible institutional treatment plan. Under the Criminal Justice Act of 1964 and the Prisoner Rehabilitation Act of 1965, probation officers have been involved in verifying home furlough plans, evaluating work release programs, and working with the Bureau of Prisons on various community initiatives.

In 1946, federal probation officers were required for the first time to submit presentence investigation reports to the court before the imposition of a sentence or the granting of probation (Fed. R. Crim. Pro. 32 (c)). These reports have assisted federal judges in interpreting and applying the guidelines enacted pursuant to the Sentencing Reform Act of 1984. In the Speedy Trial Act of 1974 (88 Stat. 2086) Congress established provisions for pretrial services at the federal level. The act was intended to reduce the unnecessary detention of persons accused of committing federal crimes and to reduce crime by such persons if they were released pending trial. Title II of the act authorized the Administrative Office to establish "demonstration" pretrial services agencies in ten judicial districts, half of which were placed under the general supervision of existing probation departments, and half of which were set up as independent entities run by a chief pretrial services officer. The Pretrial Services Act of 1982 (96 Stat. 1136) authorized the director of the Administrative Office to establish pretrial service programs in each of the remaining judicial districts except the District of Columbia. As of 2002, more than one-third of the ninety-four judicial districts had separate pretrial service offices headed by a chief pretrial services officer.

Further Reading:
Evjen, Victor H. "The Federal Probation System: The Struggle to Achieve It and Its First 25 Years," Federal Probation (June 1975): 3-15.

Meeker, Ben S. "The Federal Probation System: The Second 25 Years-1950-1975," Federal Probation (June 1975): 16-25.

Wanger, Betsy Kushlan. "Limiting Preventive Detention Through Conditional Release: The Unfulfilled Promise of the 1982 Pretrial Services Act," Yale Law Journal 97 (1987): 320-340.

Weller, Miriam Damick. "The Development of the Federal Probation System," The Social Science Review 18 (March 1944): 42-58.