Rep. Darrell Issa (R-Calif.) on Thursday sent a letter to the State Department demanding more information about the talking points the Obama administration used in the wake of last year’s deadly terrorist attack on a U.S. diplomatic post in Benghazi, Libya.

Issa says emails he obtained through a subpoena indicate that State Department leadership signed off on talking points that said the attack was due to a spontaneous protest, even though they were aware of a potential terrorist threat in the region at the time of the attack.

“One of your e-mails made clear that some of your colleagues at the State Department headquarters shared these concerns [of a potential terrorist attack],” Issa wrote in a letter to former State Department spokeswoman Victoria Nuland, “You wrote that changes to the talking points did not ‘resolve all my issues or those of my building leadership.’”