▶ Watch Video: Controversy swirls over Trump’s handling of White House documents The National Archives and Records Administration found classified materials in the 15 boxes of records it retrieved from former President Donald Trump’s residence at Mar-a-Lago, according to a letter sent to the House of Representatives’ Committee on Oversight and Reform on Friday. “NARA has identified items marked as classified national security information within the boxes,” archivist David S. Ferriero wrote in the letter. “Because NARA identified classified information in the boxes, NARA staff has been in communication with the Department of Justice.” Also in his letter, Ferriero said the National Archives found certain social media records were not captured and preserved, and Trump administration staffers “conducted official business using non-official electronic messaging accounts that were not copied or forwarded into their official electronic messaging accounts.” It is working to get the missing records. Ferriero also confirmed that some of the records it received from the Trump administration had been torn up. A portion of them had been taped back together by White House staff, while others had not been reconstructed. This file photo shows U.S. President Donald Trump’s Mar-a-Lago resort in Palm Beach, Florida, on November 22, 2018. Mandel Ngan/AFP via Getty Images Ferriero said the National Archives is still in the process of inventorying all 15 boxes but expects to be finished by February 25. The letter was sent to the House Oversight and Reform Committee, which is investigating Trump’s record-keeping practices, after it requested information from Ferriero about the boxes. The National Archives obtained the presidential documents and communications from Trump’s Florida residence last month. Under the 1978 Presidential Records Act, sitting presidents and their staff are required to preserve all memos, letters, emails, documents and official communications related to the president and then transfer them to the National Archives after the end of their term. Earlier this month, the National Archives reportedly asked the Justice Department to investigate Trump’s handling of presidential documents. The Justice Department did not comment on a possible investigation, nor did the National Archives. “We do not comment on potential or ongoing investigations,” a National Archives spokesperson said. National Archives asks DOJ to investigate Tru… 01:35 The National Archives’ request does not mean an official investigation has begun, but is standard procedure in the case of potential criminal violations, a source told CBS News. Anne Weismann, a lawyer who represented watchdog groups that have sued Trump over violations of the Presidential Records Act, told CBS News that the former president “clearly violated” the Presidential Records Act in “multiple ways,” including by ripping up records. Trump has pushed back against the narrative that he willfully destroyed important documents, saying the transfer of the boxes to the National Archives was an important step in preserving records from his administration. “The media’s characterization of my relationship with NARA is Fake News. It was exactly the opposite!” Trump said. “It was a great honor to work with NARA to help formally preserve the Trump Legacy.” Zak Hudak and Jacob Rosen contributed to this report.