Her mother wept and the courtroom burst into applause as the Supreme Court said today that four of the men held guilty of raping and torturing a 23-year-old medical student on a moving bus in Delhi in December 2012 will hang. The top court described the crime as a "story of a different world" saying the "brutal and demonic" crime had been proved beyond doubt. "If ever a case called for hanging, this was it," said the three judges, confirming the death penalty handed by two courts. But do death sentences really act as deterrents? What does the Nirbhaya verdict mean for the safety of women in this country?