The chalk man / C. J. Tudor.

Looking back, it all started on the day of the fair and the terrible accident. When twelve-year-old Eddie first met the Chalk Man. It was the Chalk Man who gave Eddie the idea for the drawings: a way to leave secret messages between his group of friends. And it was fun, to start with, until the figures led them to the body of a young girl. That was thirty years ago and Ed thought the past was behind him. Then he receives a letter containing just two things: a piece of chalk, and a drawing of a stick figure. As history begins to repeat itself, Ed realises the game was never over... Everyone has secrets. Everyone is guilty of something. And children are not always so innocent.