A court in Pakistan has released an American who shot dead two men in Lahore in January 2011 - after documents were produced which said the families of the murdered men had pardoned him after receiving "blood money". Although Raymond Davis is now free, the controversy surrounding him remains. His arrest severely strained relations between the US and Pakistan government. It continues to evoke strong public emotion and has raised anti-American feeling to an all-time high. The BBC's Syed Shoaib Hasan looks at some of the unanswered questions.