The sophistication of the bomb points to training and to the involvement of others.
Russian media report that there is a potential connection between Tamerlan Tsarnaev and a Canadian citizen, William Plotnikov, a suspected jihadist who was killed by the Russian security services in July 2012. (more here)
The older brother, Tamerlan Tsarnaev, 26, and 19-year-old Dzhokhar Tsarnaev allegedly assembled at least four types of improvised explosive devices in the home Tamerlan shared with wife Katherine Russell, sources tell Fox News. Typically, in cases of homegrown terror, only one type of explosive is constructed. (more here)
"I can't comment on any of the specifics on the design of the weapon that went off, but it is very clear when you take the totality of it that there was some outside counsel to these individuals on how to build and how to detonate," Republican Rep. Mike Rogers, chairman of the House Intelligence Committee, said.
Dzhokhar And Tamerlan Tsarnaev Planned July 4th And Suicide Attacks, Opted For Pressure Cooker Bomb: Officials
Huff Po, may 2, 2013
The surviving brother of the Boston bombing suspects told interrogators that the pair considered suicide attacks and an assault on July 4th, a law enforcement official told The New York Times.
Dzhokhar Tsarnaev, 19, who is currently in custody and has been interrogated by the FBI, reportedly said he and his brother, 26-year-old Tamerlan, opted for pressure cooker bombs that they eventually used in the twin Boston Marathon bombings on April 15, the official said.
NBC News reports that the bombs were built inside Tamerlan's house in Cambridge, Mass., and that since they were finished faster than anticipated, the brothers decided to move up the attack date.
Dzhokhar reportedly admitted to the newly revealed plots on April 21, two days after he was captured in Watertown. He also told interrogators that he and Tamerlan had watched sermons of Anwar al-Awlaki online. The Times reports that there's no indication the two had been in contact with Awlaki.
The body of Tamerlan, who was killed several days after the bombing during a shootout with police, was claimed by his family on Thursday.