One of Sweden's most popular rappers was shot dead in Stockholm late on Thursday, heightening outrage over gang-related violence that has afflicted the Nordic country in recent years. Einar, 19, whose real name was Nils Gronberg, was killed in the upmarket Stockholm suburb of Hammarby Sjostad, and no arrests had been made so far. In a previous incident last year, Einar was abducted and assaulted by rival rappers. "A young life has been extinguished, and I understand that he meant a lot to many young people. It is tragic," Prime Minister Stefan Lofven told TT, Sweden's national news agency. Gronberg,...