The Department of Justice is expanding its criminal probe into the events of Jan. 6 to include preparations for the rally that preceded the storming of the U.S. Capitol, as well as the financing for the event, multiple sources familiar with the matter tell ABC News.

       Over the past two months, grand jury subpoenas have been sent to those who assisted in the organizing and planning of former President Donald Trump's "Save America" rally on the Ellipse near the White House, the sources said.

       The news of the expanding probe was first reported by the Washington Post.

       The subpoenas to individuals with knowledge of the event are expansive, the sources said. Prosecutors are seeking multiple records and documents related to the rally, including text messages and emails, as well as potential communications with other individuals regarding the logistics of the event.

       MORE: Many Jan. 6 rally organizers poised to comply with committee, top Trump aides expected to rebuff

       Officials with the Department of Justice declined to comment to ABC News.

       The subpoenas are not indicative of wrongdoing, and one source said some subpoenas were sent with the clear indication that the request was for witness testimony and cooperation.

       Tasos Katopodis/Getty Images

       President Donald Trump arrives at the "Stop The Steal" Rally, Jan. 6, 2021, in Washington, D.C.

       "In circumstances like those of Jan. 6, a full accounting does not suddenly materialize. To ensure that all those criminally responsible are held accountable, we must collect the evidence," Attorney General Merrick Garland said in a speech on Jan. 5, one year after the Capitol attack.

       "We follow the physical evidence. We follow the digital evidence. We follow the money. But most important, we follow the facts -- not an agenda or an assumption. The facts tell us where to go next," Garland said.