Davis’s revelation came as the surviving suspect, 19-year-old college student Dzhokhar Tsarnaev, remained unable on Sunday to speak with a bullet wound to the throat after his capture from a tarpaulin-covered boat in a suburban backyard.
The suspects in Monday’s twin bombings at the Boston Marathon finishing line that killed three and wounded more than 180 are two ethnic Chechen brothers from southern Russia who had been in the US for about a decade – Dzhokhar Tsarnaev and his 26-year-old brother, Tamerlan who was killed on Friday in a shoot-out with security forces.
Authorities found many unexploded homemade bombs at the scene of the brothers’ gun battle early on Friday with police, along with more than 250 rounds of ammunition.
The stockpile was “as dangerous as it gets in urban policing”, Davis said.
“We have reason to believe, based upon the evidence that was found at that scene – the explosions, the explosive ordnance that was unexploded and the firepower that they had – that they were going to attack other individuals,” he told CBS.
Davis told Fox News that authorities cannot be positive there are not more explosives somewhere that have not been found. But he insisted the people of Boston are safe.
The ABC and NBC news networks reported late on Sunday that Dzhokhar Tsarnaev had regained consciousness and was responding in writing to questions put to him by authorities.
He was being watched by armed guards in the intensive care unit of Boston’s Beth Israel Deaconess Medical Centre.
Authorities would not comment on whether Dzhokhar Tsarnavev had been questioned.
It was not clear whether he was shot by police or wounded himself.
In the final standoff with police, shots were fired from the boat, but investigators have not determined where the gunfire was aimed, Davis said.
Tsarnaev could be charged any day.
The federal public defender’s office in Massachusetts said it has agreed to represent Dzhokhar Tsarnaev once he is charged.
