Catherine Field: Europe Correspondent on France implementing a maximum terrorist alert in response to the shooting in Moscow

France is on maximum alert in response to a shooting in Moscow.  At least 137 people were killed and 150 injured when gunmen opened fire at a rock concert over the weekend.  An urgent meeting of the Defense and National Security Council saw the alert implemented and 4000 additional members of the Sentinel team out and about in France.  Europe Correspondent Catherine Field told Mike Hosking that the heads of the security services will meet again on Thursday to review the security and decide whether new measures should be put in place ahead of the Easter Break.  LISTEN ABOVE See omnystudio.com/listener for privacy information.