Two months ago 24-year-old Juan Francisco, along with six others, was killed by members of a Mexican drug cartel. Francisco's father is Mexican poet Javier Sicilia. Juan Francisco was just one of the estimated 34,000 people killed in Mexico in drug-related violence in the last four years. Now Sicilia is leading a 900 mile march across Mexico visiting cities where people have been affected by drug violence.   Irene Caselli, will join them, she's reporting this story for the BBC.