Two suspects in the Boston Marathon bombing – identified to The Associated Press as coming from the Russian region near Chechnya – killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during their getaway attempt in a long night of violence that left one of them dead and another still at large Friday, authorities said.

A law enforcement intelligence bulletin obtained by the AP identified the surviving bomb suspect as 19-year-old Dzhokhar A Tsarnaev of Cambridge, Massachussets.