A Delhi court on Saturday convicted two cab drivers for killing Australian tourist Dawn Emilie Griggs after raping her four years ago.The court said that the prosecution has proved its case against the drivers - Jyotish Prasad and Ashish Kumar – for raping and killing the woman, a foreign tourist."Jyotish Prasad and Ashish Kumar, the offence of killing and raping against foreigner lady after robbing her of valuables is proved against you," Additional Sessions Judge Vinod Kumar said, holding the duo guilty in the case.The court is likely to pronounce quantum of sentence, which may range from life imprisonment to death sentence, on August 4.