This image contained in a court filing by the DOJ on August 30, 2022, and partially redacted by the source, shows a photo of documents seized during the August 8 FBI search of former President Donald Trump's Mar-a-Lago estate.
CNN  — 

Special counsel prosecutors have secured evidence including daily notes, texts, emails and photographs and are focused on cataloging how Donald Trump handled classified records around the Mar-a-Lago resort and those who may have witnessed the former president with them, according to multiple sources familiar with the investigation.

The new details come amid signs the Justice Department is taking steps typical of near the end of an investigation.

The recent investigative activity before a federal grand jury in Washington, DC, also includes subpoenaing witnesses in March and April who had previously spoken to investigators, the sources said. While the FBI interviewed many aides and workers at Mar-a-Lago nearly a year ago voluntarily, grand jury appearances are transcribed and under-oath – an indication the prosecutors are locking in witness testimony.

Another source familiar with the matter told CNN that Secret Service agents tasked with protecting the former president have been called to testify. The number of agents remains unclear. Fox first reported on the development.

The focus of both the mishandling of records and obstruction of justice probes has remained on the actions of the former president, the multiple sources familiar said. That includes prosecutors pursuing evidence of Trump’s intent to keep classified records after he left the White House, plus his knowledge that the records remained in his possession after the Justice Department demanded their return last May.

Witnesses are being questioned about what they saw in Trump’s private residential and work areas within the club, some of the sources said.

Investigators have also collected texts and notes from Molly Michael, Trump’s assistant, which detail what Trump was doing and who he was meeting with in his day to day.

The new evidence the team working for special counsel Jack Smith is focusing on is separate from what was obtained through a recent grand jury pursuit of Trump’s defense lawyer Evan Corcoran, a source told CNN. Corcoran spoke with the former president the day the Trump Organization received a subpoena for Mar-a-Lago surveillance tapes and at other pivotal moments last year, and the DOJ believes Trump used the lawyer to try to advance a crime.

Steven Cheung, a spokesman for Trump, accused the Justice Department of “prosecutorial misconduct” and leaks in the investigation, when asked to respond to recent developments in the classified documents investigation.

A spokesman for the special counsel’s office did not immediately respond to a request for comment.

The grand jury activity – expected to continue to occur at a frequent clip in the coming weeks – builds upon several known reactions Trump and others around him had to the DOJ’s attempt to reclaim classified records last year, and which prompted the FBI to obtain a judge’s approval to search Mar-a-Lago in August for classified records.

Some of the evidence the DOJ has used to persuade a judge to allow that search is still under seal.

The unprecedented search of the former president’s residence recovered more than a hundred documents marked as classified.

The grand jury activity also appears to be in line with more than two dozen subpoenas sent to aides and resort staff at Mar-a-Lago that has underlined investigators’ continued interest in what they saw or heard around the estate.

The FBI search came months after the DOJ had subpoenaed all classified documents and developed evidence, including by viewing the resort’s surveillance footage, that Trump hadn’t return all that he had. One aide has told investigators Trump directed him to move boxes from a basement storage room to his residential area in the club following the DOJ’s subpoena for all classified records, CNN previously reported.

Since then, the Justice Department has pushed for answers around how a box with classified records ended up in Trump’s office after the FBI search took place. Trump lawyers have downplayed items with classified markings they found at the resort late last year, such as an empty manila folder marked as containing a classified summary. One Trump defense attorney said the ex-president used the folder to block a light in his bedroom that kept him up at night.

This story has been updated with additional reporting.

CNN’s Kaitlan Collins contributed to this report.