A makeshift memorial to MIT Police Officer Sean Collier was erected by a steady stream of visitors in front of Building 32 on Friday, April 19, 2013. Ho Yin Au—The Tech May. 9, 2016 Facebook Twitter Reddit Print A makeshift memorial to MIT Police Officer Sean Collier was erected by a steady stream of visitors in front of Building 32 on Friday, April 19, 2013. Ho Yin Au—The Tech