Kelly says the two suspects had a pressure cooker bomb and five pipe bombs they wanted to set off.
They said Dzhokhar Tsarnaev (joh-KHAHR' tsahr-NEYE'-ehv) told Boston investigators from his hospital bed that he and his brother had discussed going to New York to detonate their remaining explosives. They said they decided it spontaneously.
Kelly had said a day earlier that the Boston Marathon bombing suspects were planning to party in New York, but was later briefed by federal officials.
Tsarnaev traveled to New York at least once last fall. There is a photo of the suspect in Times Square.
Tsarnaev's older brother, Tamerlan (TA'-mehr-luhn), died in a shootout with police.