Federal Criminal Procedure 101: Probable Cause and the Grand Jury

When one of the federal investigative agencies believes that it has evidence of a violation of United States law, the investigative agents will present their findings to the Office of the U.S. Attorney in their district.  One of the Assistant U.S. Attorneys will review the case and question the agent about it in detail to determine whether the evidence shows that there is probable cause to believe a crime has been committed. 

If the evidence is not sufficient to establish probable cause, the Assistant U.S. Attorney (AUSA) may ask the agents to continue their investigation, in the alternative, he or she may decide that the evidence should be presented to a grand jury and that the grand jury should continue the investigation of the case. 

If the AUSA determines that there is probable cause, he or she will present the evidence to the grand jury and ask that they vote on a proposed criminal charge.  This charge is called an indictment.  However, in some instances, there is insufficient time to present the case to the grand jury because of an urgent need to arrest the person believed to have committed the offense. 

In these instances, the AUSA will ask a judge to issue an arrest warrant based on a sworn statement called a complaint, which sets out the essential facts of the offense charged.  The complaint, or sworn statements filed with the complaint, must also set out evidence sufficient to establish probable cause to believe that the specific crime charged was committed by the person charged with that crime.  If, after a careful review, the judge determines that there is sufficient evidence to meet the probable cause standard, the judge will issue a warrant for the arrest of that person.  If a person is arrested pursuant to this procedure, the AUSA must thereafter present the case to the grand jury and obtain an indictment.

A grand jury consists of between 16 to 23 citizens who have the duty, after reviewing the evidence, to vote on a proposed criminal charge.  Generally, the grand jury hears evidence only from the government.  A target of an investigation (i.e., a person on whom the investigation is focused) may not be subpoenaed before a grand jury but may volunteer testimony before the grand jury.  This seldom occurs. 

In order for a person to be indicted, at least 12 members of the grand jury must find that there is probable cause to believe that the person or persons to be charged committed the crime or crimes to be charged.  While the grand jury is deliberating on whether to return an indictment, i.e., to issue an indictment, the prosecutor and the agent, court reporter, and everyone else must remain outside the grand jury room. 

Persons accused of crimes punishable by more than one year’s imprisonment have a Constitutional right to be indicted by a grand jury. The grand jury does not determine the guilt or innocence of the defendant.  That can be done only at trial. 

A federal prosecutor does not have the authority to issue a subpoena ordering a person to give testimony or to produce evidence in his or her possession.  The grand jury has the authority to issue such subpoenas, and it therefore has substantial investigative powers.  In practice, the AUSA or other federal prosecutor usually issues subpoenas in the name of the grand jury.  However, the grand jury can subpoena additional witnesses of its own volition. 

When a witness is subpoenaed before the grand jury, the AUSA generally asks the questions although in many instances the grand jurors also question witnesses.  A witness before a grand jury, like a witness at a trial, may not be compelled to give evidence that would tend to show that he or she has committed a criminal offense.  As discussed above, this right is referred to as the Fifth Amendment privilege or the privilege against self-incrimination.

Grand jury proceedings are recorded verbatim by a stenographer and are secret.  It is a crime for a prosecutor or a member of the grand jury to discuss grand jury proceedings in public.  Also, a prosecutor may not disclose grand jury information to another prosecutor or investigating officer, unless that prosecutor or officer is also involved in the same criminal investigation.  Information gathered by a grand jury may be disclosed only upon the order of a federal court. Such permission is rarely given.  Of course, evidence obtained by the grand jury may be used later at trial, if the grand jury formally indicts one or more persons for a criminal offense.

In complex crimes such as most bank frauds {or health care fraud}, the involvement of a grand jury from the beginning is essential to an effective investigation.  In such cases, the prosecutor and investigator will work very closely together from the start of the investigation. 

source quoted from here