President Obama has said authorities who hunted down the Boston bomb suspect had "closed an important chapter in this tragedy" with his capture.
Speaking at a news conference, the president paid tribute to the police officer who died in yesterday's shootout at MIT campus and said "unanswered questions" remained as to the motivation of the suspected bombers.
Among those terribly injured by the Boston marathon bombs was a dance instructor. Adrianne Haslet-Davis lost her foot in the explosion.
The mother of the two brothers suspected of carrying out the Boston bombings told ITV News they saw last year's race but are innocent.
Boston's marathon bombing suspect Dzohkhar Tsarnaev was charged with an offence that could lead to the death penalty, if he is found guilty.