Grand Jury and Grand Jury Powers: What This Means for Trump
Because we can't go more than four hours without breaking news, almost everyone has heard by now that Special Counsel Robert Mueller began using a grand jury in Washington several weeks ago as part of his investigation into potential ties between the Trump campaign and the Kremlin. This may seem like a fairly obvious term, but it's pertinent to explain clearly what exactly a grand jury is and what powers it has.
A grand jury is "a legal body empowered to conduct official proceedings and investigate potential criminal conduct, and determine whether criminal charges should be brought." A grand jury may demand to see documents and have witnesses appear before it, but it is not the same as a trial jury. A grand jury does not have the power to convict someone of a charge, only to determine whether or not charges should be made against someone.
Grand juries can accomplish two major things: they can investigate a crime and they can then accuse someone of a crime. These are called their "accusatory and investigatory functions." The investigatory function endows them with the right to obtain and review documents and to receive testimony from witnesses. The accusatory function endows them with the right to assert that there is probable cause to believe that someone committed a crime.
Trial juries meet in a public forum, that is to say the public is allowed to see everything that they are. Grand juries, however, meet in secret so as to allow witnesses to speak freely and the investigative process to be free from outside influence.
What does Mueller's use of a grand jury imply for the Trump case? Well, it certainly implies that evidence is being gathered as the investigation is taking place. It also implies that witnesses will be subpoenaed to appear before the grand jury and testify; notably, many of the highest ranking members of the F.B.I. may be asked to come before this jury. If Mueller has moved the investigation to an evidence-gathering phase, it could mean that charges are being considered. It could also mean that the investigation is just becoming more thorough. Either way, grand juries are known for indicting more often than not, so even if Trump himself comes out of this without criminal charges, someone undoubtedly will.