Some prominent Democrats are calling for Attorney General William Barr to resign after the release of a letter from Special Counsel Robert Mueller revealed that Barr may not have been truthful when testifying to Congress earlier this month.

The letter, which Mueller sent Barr in late March after the attorney general released his four page summary of the Special Counsel's investigation, expressed concern that Barr's handling of the report was creating “public confusion about critical aspects of the results of our investigation.” However, when asked by Rep. Charlie Crist in April whether Barr was aware that members of the special counsel's team were dissatisfied with the way Barr represented their findings, Barr denied it.

Joining Boston Public Radio to discuss this topic was homeland security expert Juliette Kayyem. Kayyem is on the faculty of Harvard’s Kennedy School and is a CNN analyst.

"There's no both sides-ism. He was asked a direct question and he lied," Kayyem said.

"[Barr] was in possession of a letter in which Mueller expressed concerns about the four pager and representations of the report. [Barr] said no, he was unaware. That is a lie," she continued.

Democratic Sen. Mazie Hirono told Barr Wednesday that she believed he lied to Congress and should resign. Kayyem echoed the sentiment that Barr deliberately misled Congress.

"We don't need to be shy. He perjured himself," Kayyem said.