Once a defendant is arrested by federal agents, a probation officer conducts an expeditious, yet thorough background investigation of the defendant. The majority of the information is provided by the defendant during an interview shortly after arrest, which is normally conducted just prior to the defendant's first appearance in court. After interviewing the defendant, the probation officer will either corroborate or challenge the information provided by the defendant, and obtain additional information. The probation officer's investigation may include contacting the defendant's family, friends, associates, law enforcement agencies, and/or financial institutions. The information provided by the defendant is not used to determine guilt, but rather the defendant's suitability for release from federal custody. The probation officer's duty is to identify defendants who are likely to fail to appear at future court hearings, or are likely to present a threat to the community. The probation officer must balance the presumption that the defendant is "innocent until proven guilty," with the reality that some defendants may flee the jurisdiction or present a threat to the community.

If the probation officer believes there is a likelihood the defendant may fail to appear in court, the officer recommends a financial bond, which the defendant or the defendant's "surety" (usually a family member, business associate or close friend) would forfeit should the defendant fail to appear in court. In addition, the probation officer may recommend conditions of release such as: not to possess weapons; not to have contact with victims or witnesses; not to use alcohol or drugs; restricting the defendant's travel and/or with whom the defendant associates; requiring the defendant to seek and maintain employment; requiring the defendant to obtain education or training; and surrender a passport, among others. Release conditions are tailored to the individual defendant, but always include the standard condition that the defendant is not to commit any crimes during the period of release. In any case, it is the probation officer's statutory responsibility to recommend the least restrictive conditions that would reasonably assure the defendant's appearance in court. If no combination of conditions ensures future appearance, or if the defendant is viewed to be a danger to the community, detention is then recommended.

Once the investigation is completed, the probation officer submits a report to the court with the appropriate recommendation which assists the court in making an informed decision regarding the defendant's release or detention pending trial. If the defendant is released on bond, probation officers monitor compliance, provide necessary support services, and inform the court and the U.S. Attorney's Office of all apparent violations of supervision. The probation officer will supervise the defendant until the defendant's case is disposed.