Update: Asked about claims that requests for additional security in Benghazi were denied, White House Press Secretary Jay Carney refused to comment, citing an ongoing investigation by the FBI. Nearly three weeks after the attack, FBI agents sent to Libya to investigate have yet to set foot in Benghazi.

In another additional detail not contained in his letter, Issa says there were a total of 13 threats and/or attacks on the U.S. consulate in Benghazi prior to the September 11 attack.

[End update]

The security lapses in Benghazi that led to the death of Ambassador Stevens and three other Americans trace back to security decisions made in Washington. That’s the message of a letter Rep. Darrell Issa sent to Secretary Clinton Tuesday. The letter indicates that the US mission in Libya made repeated request for increased security prior to the September 11th attack but that these requests were denied. Issa’s House Oversight committee is planning a hearing on Wednesday, October 10, to investigate the failure.

Issa’s letter is an effort to gather relevant information on security arrangements in Libya prior to the attack. In particular, Issa is requesting information on security requests from the Libyan Embassy and relevant documents on how those requests were handled. According to the letter, “multiple U.S. federal government officials have confirmed to the Committee that, prior to the September 11th attack, the U.S. mission in Libya made repeated requests for increased security in Benghazi. The mission in Libya, however, was denied these resources by officials in Washington.”

The letter offers a partial timeline of attacks on western outposts in Tripoli and Benghazi which shows a pattern of targeting western diplomats and outposts. It also suggests the attacks were escalating in their boldness, i.e. late night attacks give way to strikes in broad daylight. What follows is summary of the incidents mentioned in Issa’s letter:

While the list suggests a clear pattern it is far from complete. For instance, in April a bomb was thrown at a convoy carrying the head of the UN mission to Libya as he traveled through Benghazi.

The letter requests a written response to three questions. Did the State Department know about all of the above attacks? What security arrangements were made in light of them? What requests did the Libyan Embassy make for additional security prior to September 11, 2012? Issa requests that a written answer be provided to the committee by Monday October 8th.