Sean Collier was a member of the SAPD from 2006 to 2009, rising to the rank of Sergeant. Sean was the youngest Sergeant in the history of SAPD and left a positive mark upon all those who he encountered. Sean was a Massachusetts Institute of Technology (MIT) Police Officer when was murdered in the line of duty on April 18th, 2013, by the Boston Marathon terrorists. He was to join the Somerville Police Department as a full-time police officer in just weeks. On Aug 22, 2013 Sean’s lifelong dream of being a Somerville Police Officer was fulfilled. He was posthumously sworn-in by the Somerville Board of Aldermen. Sean was assigned badge #310 which was immediately retired, never to be reissued.