According to timelines, the State Dept issued an email [to personnel and other government agencies] at 6:06 p.m. ET on 9-11-2012 saying Ansar al-Sharia claimed responsibility for the attack.
[That was even before the 10:00 p.m. ET phone discussion between Clinton and Obama, and the 10:30 p.m. ET on 9-11-2012 statement from Hillary Clinton that blamed “inflammatory material posted on the Internet” for the violence.]
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Extensive timeline:
http://directorblue.blogspot.com/2013/05/damning-benghazi-timeline-spreadsheet.html
BTTT!