During the tenth day of the Boston Marathon bombing trial, U.S. Prosecutors on Thursday cited numerous documents, music files and sermons extracted from computers and other devices used by Dzhokhar Tsarnaev as evidence of his link to radical Islam.

Over the course of the day, Special Agent, Kevin Swindon,  who heads the FBI's "cyber squad" in Boston, explained what can be recovered on computers even if the  information is erased or hidden. It was a crash course in computer technology that covered cellphones, iPods, thumb drives and a Sony laptop.

On one laptop investigators found more than 500,000 files. The data included copies of entire issues of a magazine called inspire in PDF form. It is published by – al Qaeda in the Arabian Peninsula.  This included an article titled “How To Build A Bomb In The Basement Of Your Mom.”  

But if the government was trying to show that these items were the sole property of Dzhokhar, they may not have succeeded all together. A desktop computer taken from the Tsarnaev family's rented apartment on Norfolk Street in Cambridge had multiple usernames and when an assistant prosecutor asked if the computer was used by only one person, or by many, Swindon responded :

“I think it was used by many people,”  thus possibly pointing a finger at the older brother Tamerlan, among other users.  

Swindon also testified that his team found on computer-related devices belonging to or used by Dzhokhar of “Nasheed” music, which is described as music adapted as “a cappella battle hymns” of global jihad

The prosecution said that these included  a song titled "The man who went to Jannah without praying… "  that can be found on You Tube —  translation.

Investigators, according to Swindon, also found religious music CD's in the carjacked Mercedes and in Tsarnaev's  Green Honda the night of the shootout in Watertown.

The government said a search of devices in Tsarnaev’s dorm room at  UMass Dartmouth and at his home on Norfolk Street in Cambridge, uncovered sermons by the radical Muslim cleric Anwar Al Awlaki,, an American citizen targeted by the US government in Yemen who advocated terrorism against the United States.  Al Awlaki died in a drone strike in 2011.