Secretary of State John Kerry made an indirect reference to the radicalisation of Tamerlan Tsarnaev that apparently occurred when he travelled to Dagestan and Chechnya on a six-month trip during late 2012.

In remarks made with Belgian Foreign Minister Didier Reynders in Brussels on Wednesday, Mr. Kerry, referring to Tamerlan, said, “We just had a young person who went to Russia, Chechnya, who blew people up in Boston. So he didn’t stay where he went, but he learned something where he went and he came back with a willingness to kill people.” Quizzed about his comments, the State Department however directed media to the FBI, charged with the criminal investigation into the bombing, saying, “The Secretary was simply expressing broad concern about radicalism and not necessarily offering any more specific information about this case.”

According to officials who spoke to the Associated Press, Tamerlan was added 18 months ago to a massive classified database of known and suspected terrorists, the Terrorist Identities Datamart Environment (TIDE). This action came directly after a 2011 query from Russian authorities, who expressed concerns to the CIA that he had become radicalised.

This week members of the U.S. Congress and intelligence officials came out strongly against what they described as significant “intelligence failures” relating to the FBI and Republican Senator Lindsey Graham, for example, said the agency had “dropped the ball”.

Even as criticism mounted on this front, the prosecution’s case against the surviving bombing suspect, younger brother Dzhokhar, appeared to face a setback when the 19-year-old reportedly “went silent” after being read his constitutional rights.

Officials said that Dzhokhar “immediately stopped talking after a magistrate judge and a representative from the U.S. Attorney’s office entered his hospital room and gave him his Miranda warning”, the Associated Press reported.

However before being advised of his right to remain silent, Dzhokhar had told authorities that Tamerlan “only recently had recruited him to be part of the attack that detonated pressure-cooker bombs at the marathon finish line”.

More In: World | International | News