Boston bomber Dzhokhar Tsarnaev told investigators that he and his brother acted alone and learned to build the pressure-cooker bombs over the Internet, nbc.com reports.
Dzhokhar Tsarnaev also told investigators that he and his brother got instructions on building bombs from an online magazine published by al Qaeda, federal law enforcement officials told NBC News. He said they read the instructions in Inspire, an online, English-language magazine which al Qaeda began publishing in 2010.
Tsarnaev has said too that they were motivated by a desire to defend Islam because of “the U.S. wars in Iraq and Afghanistan.”