Complex sentence: However, according to the 9/11 Commission Report the CIA had identified Khalid Sheikh Mohammed's alias in August 2001: The final piece of the puzzle arrived at the CIA's Bin Ladin unit on August 28 in a cable reporting that KSM's nickname was Mukhtar.
Split into simpler sentences: However, according to the 9/11 Commission Report the CIA had identified Khalid Sheikh Mohammed's alias in August 2001. According to the 9/11 Commission Report, The final piece of the puzzle arrived at the CIA's Bin Ladin unit on August 28 in a cable reporting that KSM's nickname was Mukhtar.