WASHINGTON -- U.S. officials investigating the Boston Marathon bombings have told The Associated Press that there is no evidence to date of a wider plot.
But the chairman of the House Homeland Security Committee says the FBI is investigating in the U.S. and overseas to determine whether Tamerlan (TAM'-ehr-luhn) and Dzhokhar Tsarnaev (joh-HAHR' tsahr-NEYE'-ehv) received training.
Rep. Michael McCaul tells "Fox News Sunday" the shrapnel-packed pressure cooker bombs used in the attacks leads him to believe that someone did train the bombers. Homemade bombs built from pressure cookers have been a frequent weapon of militants in Afghanistan, India and Pakistan. Al-Qaida's branch in Yemen once published an online manual on how to make one.
McCaul also tells "Fox News Sunday" that he thinks the suspects' mother played "a very strong role" in her sons' radicalization process and that if she were to return to the United States from Russia, she'd be held for questioning.
Russian's internal security service is refusing comment on reports that it secretly recorded a telephone conversation in 2011 in which one of the Boston bombing suspects discussed jihad with his mother.
The U.S. government received details about the call a few days ago and officials describe the conversation as vague. They say Tamerlan Tsarnaev (TAM'-ehr-luhn tsahr-NEYE'-ehv) and his mother discussed the possibility of going to Palestine, but he told his mother he didn't speak the language.