over safety concerns. french police have arrested a man. three members of the family and a passing cyclist was shot dead on a remote mountainside road. it is a read of element in one of france s most notorious unsolved cold cases. our paris conned respondent explained earlier that the news needs to be taken with caution. i should say before we start at this point does not mean there has been a breakthrough, there are words of great caution coming from the french alps about this. it s not the first time there have been arrests, people have been called in for questioning, every now and again, it s a very long drawn out investigation. possibly this is significant but quite possibly not. let s notjump