The murder of a policewoman and the bloody siege at a Jewish supermarket carried out by a known associate of the two suspects in the Charlie Hebdo massacre indicates that an organised group was behind last week's terror attacks. Mediapart has had access to documents from an anti-terrorist investigation in 2010 showing that two of last week's gunmen were involved back then with a radicalised French network that was considering future “martyr operations”. These were supermarket hostage taker Amedy Coulibaly and Charlie Hebdo massacre suspect Chérif Kouachi. As Fabrice Arfi and Karl Laske report, the revelations will inevitably raise questions about whether more could have been done by the intelligence services to prevent last week's bloody events.