CRIME
04/19/2013 06:48 am ET Updated Jun 19, 2013

Dzhokhar Tsarnaev, Boston Marathon Bomb Suspect, Pursued By Authorities

WATERTOWN, Mass. (AP) — Two suspects in the Boston Marathon bombing 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 as the manhunt intensified for a young man described as a dangerous terrorist.

The suspects were identified to The Associated Press as coming from the Russian region near Chechnya, which has been plagued by an Islamic insurgency stemming from separatist wars. A law enforcement intelligence bulletin obtained by the AP identified the surviving bomb suspect as Dzhokhar A. Tsarnaev, a 19-year-old who had been living in Cambridge, Mass.

Two law enforcement officials told the AP that Tsarnaev and the other suspect, who was not immediately identified, had been living legally in the U.S. for at least one year.

In Boston, still on edge over the attack on the marathon, and its western suburbs, authorities suspended mass transit and urged people to stay indoors as they searched for the remaining suspect, a man seen wearing a white baseball cap on surveillance footage from Monday's deadly bombing at the marathon finish line.

"We believe this man to be a terrorist," said Boston Police Commissioner Ed Davis. "We believe this to be a man who's come here to kill people."