Special Counsel Robert Mueller has impaneled a Washington, D.C. grand jury for his probe of Russia’s interference in the 2016 election, according to a Wall Street Journal report.
On "Your World," Judge Andrew Napolitano explained that grand juries are powerful investigative tools that allow prosecutors to subpoena documents, put witnesses under oath and seek indictments, if there is evidence of a crime.
"It doesn't mean they have a target. It doesn't mean they think somebody's guilty. It just means they need this tool, this instrument called a subpoena, in order to gather more information to decide where to go next," Napolitano said.
He explained that a grand jury consists of 23 jurors, impaneled in secret.
"You put a witness on before them. In this case, probably an FBI agent, who will testify to what information she or he has already gathered," Napolitano said, adding that if the grand jury is moved by that testimony, they can vote to issue subpoenas.
As for reports that this signifies Mueller is ratcheting up the Russia probe to a more serious, rigorous investigation, Napolitano said he doesn't necessarily agree.
He said it is just a sign that Mueller has found something from some source, and that will be explained to the grand jury, in order to persuade them to vote to issue a subpoena.
"It doesn't mean that this is going to be over soon. It doesn't mean it's going to go on forever. It just means it's moving methodically, professionally, and there is something there worthy of the grand jury's attention," he said.
Watch more above.