Government-allied militias say they have not been told to arrest the man, identified as Ahmed Abu Khattala, in the Benghazi attack. It is unclear where he is.BENGHAZI, Libya — The militia commander who led the deadly raid on the U.S. mission in Benghazi is an Islamist and former political prisoner whose fighters were also blamed for assassinating a senior military officer after he defected to the opposition during last year's revolution against Moammar Kadafi, a senior Libyan official said.