Congress has divided the United States into federal districts and divisions for the express purpose of evenly distributing federal courthouses and personnel throughout this vast country. The districts and divisions therein were created by express legislation codified at Title 28 U.S.C. §81-131. As is evident from examination of the federal districts which were created by Congress, most states have federal districts which usually correspond with patterns of population within that state’s boundaries. On a state by state basis, these districts and divisions can be seen at Title 28 U.S.C. §81-131 on the U.S. Government Printing Office’s (GPO) website. (This current link is to the Code Section as of 2011).
Usually, for every federal district, there is a United States Attorney’s office. The United States Attorney responsible for the activities of such offices is appointed by the President of the United States, usually for a 4 year term. Besides being responsible for prosecuting all cases where federal law has been allegedly violated, the United States Attorney is also responsible for handling the government’s civil legal affairs within his/her district. Thus, United States Attorneys are not only responsible for prosecuting bank robbers, tax evaders, drug dealers and other federal felons, he is also the representative of the United States in all civil litigation within his/her district.
Usually the United States Attorney is an administrator supervising a staff of civil and criminal Assistant U.S. Attorneys (AUSA’s). In a large office, for example, the Southern District of New York, the United States Attorney responsible for that federal district may have over 200 attorneys working underneath him. In a small office, he may only have a handful. Regardless of the size of the office, however, the United States Attorney is the chief federal prosecutor in the district.
The United States Attorney’s office is usually involved in the earliest stages of any federal criminal investigation. Typically, it is an Assistant U.S. Attorney that is asked to render a preliminary opinion as to whether there is a federal prosecutorial interest in a given set of facts. If, after review of the facts, a case is accepted for prosecution by an Assistant U.S. Attorney, from that point forward, the local U.S. Attorney’s office will be intimately involved in the investigatory process.
In the course of a federal investigation, it may be necessary for the federal investigative agency to obtain a search warrant to seize certain material evidence. Typically, the federal agent will confer with an AUSA about this and will ask the AUSA to prepare a search warrant for submission to the local United States Magistrate. If an agent needs subpoena power to obtain bank or telephone records, he/she will usually request that the subpoena be obtained and prepared by an AUSA. Armed with his search warrant and/or subpoena, the agent will then execute or serve same in order to effectuate the collection of evidence in the case.
As prosecutor in a given case, an AUSA will usually want to stay closely involved with the investigative agency throughout all stages of its investigative work. Such closeness of cooperation between the prosecutor and the agent will ensure familiarity with the facts and will minimize mistakes. While federal agents are trained to assess legal considerations in their cases (such as issues of entrapment, probable cause and sufficiency of the evidence), an AUSA has far more training and is therefore in the best position to make legal judgments as a case develops. Indeed, if preliminary legal opinions are needed as investigations progress, the agent in charge of the investigation will almost always defer to the judgment of the AUSA assigned to the case.