The plot to attack the Boston Marathon reportedly was not the original plan.
FOX News Radio's Courtney Kealy reports:
Multiple reports say that the Tsarnaev brothers were planning their attack for the Fourth of July . A national security source familiar with the investigation confirmed to FOX News that Dzhokhar Tsarnaev told investigators that the bombs came together more quickly then expected so the brothers decided their "target of opportunity" would be the Boston Marathon. The planning showed clear pre-meditation including the decision to target the finish line. FOX can confirm that sources familiar with the investigation say the bombs were likely built in older brother Tamerlan's home.
Courtney Kealy, FOX News Radio.