Sign up for the Essential California newsletter to get great stories delivered to your inbox
Nation Nation Now

MIT Police Officer Sean Collier

MIT Police Officer Sean Collier, 26, of Somerville, Mass., was shot and killed on April 18 of last year. Police said Boston Marathon bombing suspects Tamerlan and Dzhokhar Tsarnaev were the ones who shot him. Middlesex District Attorney's Office / Associated Press
This photo is featured in these articles: