The 26-year-old Massachusetts Institute of Technology police officer  Shawn Collier died after he being shot in cold-blood near the Stata Center on the college campus Thursday night. A pursuit and shootout in Watertown early Friday morning that left one of the Boston Marathon bombing suspects was connected to the shooting.

A transit officer, Richard Dohohue was also shot and wounded during the early morning shootout early on Friday morning.

A timeline of events over the past 24 hours is available.