The pretrial services officer conducts the investigation before the defendant's initial appearance or pretrial release hearing before the court. The investigation begins when the officer is first informed that a defendant has been arrested. Before interviewing the defendant, the assigned officer conducts criminal history checks and may speak with the assistant U.S. attorney assigned the case for more information about the defendant, the charges, and the government's position regarding release or detention. When interviewing the defendant, the officer first explains the purpose of the interview, that the defendant will not be questioned about the offense, that there is no obligation to answer any questions, and that the court will use the information the defendant provides to determine whether the defendant will be released or detained pending further proceedings. There are a few concepts unique to pretrial services that are not applicable to other areas of community corrections. They are the least restrictive conditions of release, the presumption of innocence, and confidentiality. The article also describes how officers supervise defendants and monitor their compliance with the conditions of release imposed by the court and what officers do if defendants violate these conditions. The dual mission to investigate and to supervise is complex. Carrying it out requires officers to perform varied and specialized duties. A typical day for a pretrial services officer is described. 4 references