leonie granger , 25 , targeted playboy mehmet hassan , 56 .
but after going back to his flat with him one night she made her excuses and left the door unlocked so her boyfriend and a second thug could get inside .
they tied up the father of three and kicked him to death as they ransacked his home to find his hidden winnings .
police found damning mobile phone footage of granger and the men laughing and throwing around £ 50 notes .