Police say phone discarded by one of the terrorists contained an SMS sent to an unidentified recipient at 9.42 p.m. local time, moments before the shooting there began: “On est parti on commence” The phone also contained a detailed map of the interior of the Bataclan concert hall, according to local media reports. Cellphones can’t work unless they regularly report their location to the network, so it knows where to direct incoming calls and SMSs. Police used location information, wiretaps, search warrants, eyewitness accounts and data mined from existing intelligence reports to identify and locate the hideouts used by the terrorists.”]