Marathon bombing plot a year in making, FBI documents show

BOSTON – Dzhokhar Tsarnaev, the convicted Boston Marathon bomber, worked with his slain brother, Tamerlan, to collect components of the two pressure-cooker bombs they used to kill three people and injure hundreds of others and didn't tell anyone else about their plan, which may have been at least a year in the making, newly disclosed FBI documents show. The Cambridge residents built the bombs in Tamerlan's apartment on Norfolk Street near Inman Square, according to information from interviews w

BOSTON – Dzhokhar Tsarnaev, the convicted Boston Marathon bomber, worked with his slain brother, Tamerlan, to collect components of the two pressure-cooker bombs they used to kill three people and injure hundreds of others and didn't tell anyone else about their plan, which may have been at least a year in the making, newly disclosed FBI documents show. The Cambridge residents built the bombs in Tamerlan's apartment on Norfolk Street near Inman Square, according to information from interviews w…