Sean Collier was the Massachusetts Institute of Technology (MIT) police officer killed April 18 in the aftermath of the marathon tragedy. He was gunned down that evening while on duty in his patrol ...

faculty and staff as well as law enforcement officials from across the nation are expected to attend a memorial service for fallen campus police officer Sean Collier ...

Tsarnaev was also convicted in the killing of MIT Police Officer Sean Collier during the ensuing manhunt. In trying to avoid a death penalty sentence, Dzhokhar Tsarnaev's lawyers contended that he ...