Special counsel Jack Smith’s investigation into former President Donald Trump’s alleged role in the Jan. 6 Capitol riot appears to be heating up, with at least five Secret Service agents testifying after being issued subpoenas to appear in front of a grand jury hearing evidence in the case, NBC News reported Monday. It remains unclear what they discussed with the grand jury panel, or whether they were with Trump on the day of the riot. The case is separate from Smith’s investigation into Trump’s alleged mishandling of classified documents at his Mar-a-Lago estate, which resulted in a bombshell federal indictment earlier this month. That case saw 24 Secret Service agents provide testimony, NBC News reported.