Justice Department special counsel Robert Mueller has launched a grand jury in his investigation of Russian influence in the 2016 election.
The term grand jury is derived from the fact that it usually has a greater number of jurors than a trial jury. A grand jury typically consist of anywhere from 16 to 23 people, and the jurors may have to sit for months at a time.
Unlike a typical trial, grand jury proceedings are not public and there is no cross-examination or presentation of the defense case. The jurors may ask questions themselves and witnesses may not have lawyers present during the questioning.
Grand juries typically fulfill both a charging and investigative function. When it comes to charging, a grand jury must determine that probable cause exists to believe that an individual has committed a crime before the person can be charged for the crime. On the other hand, the grand jury has an investigative purpose by being granted the ability to subpoena documents and witnesses.
In a complicated and long-term criminal investigation, federal prosecutors will go to the grand jury to ask for the production of documents or records they deem necessary for the case. Also, if prosecutors want to force witnesses to testify under oath, they go to the grand jury to subpoena the witness.
Grand jury investigations can be long processes, lasting for months or years. The grand jury continues as the prosecutors chase evidence and leads to compile a case.
However, grand juries do not necessarily mean that charges will follow. The grand jury will determine if a crime is warranted and criminal charges should be brought at the end of the thorough investigation.