BOSTON — Two dramatically different portraits of Boston Marathon bombing suspect Dzhokhar Tsarnaev are expected to emerge when prosecutors and Tsarnaev’s lawyers give their opening statements at his death penalty trial.

Was he a submissive, adoring younger brother who only followed directions given by his older, radicalized brother? Or was he a willing, active participant in the attacks?

The trial that begins today is expected to be one of the most closely watched terror cases in years.

Three people were killed and more than 260 were hurt when twin bombs exploded near the finish line seconds apart on April 15, 2013.