FBI: Bomb components found in Tsarnaev apartment

FBI agents told jurors in the trial of the accused Boston Marathon bomber that nails, ball bearings, pressure cooker parts and other items similar to those used in two pressure-cooker bombs that exploded near the marathon's finish line were found in Dzokhar Tsarnaev's apartment in Cambridge, as prosecutors wrapped up their case against him on Thursday. 

The parts and other items purchased by Dzhokhar Tsarnaev's brother, Tamerlan Tsarnaev, were found during a search of the apartment they shared, four days after the April 15, 2013, attack. Tamerlan Tsarnaev, then 26, died days after the bombing when he was wounded during a gun battle with police and run over by Dzhokhar Tsarnaev as he tried to escape. Dzhokhar Tsarnaev, then 19, was found more than 18 hours later, hiding in a boat parked in a yard in Watertown.

Authorities say the Tsarnaevs orchestrated the bombing, in which two pressure cookers loaded with nails and BBs exploded near the finish line, killing three people and injuring more than 260 others.

Tsarnaev's lawyers have admitted that he and his brother planted and detonated the bombs, but they say Tamerlan Tsarnaev was the mastermind of the attack. Dzhokhar Tsarnaev pleaded not guilty last month to charges including using a weapon of mass destruction to kill.

Dzhokhar Tsarnaev's attorneys contend that he had not lived in the apartment since he enrolled at the University of Massachusetts at Dartmouth more than a year before the bombings, so most of what was found there did not belong to him.

The brothers, who were born in the former Soviet Union, lived in the former Soviet republic of Kyrgyzstan and the volatile Dagestan region of Russia before moving to Cambridge with their parents and two sisters about a decade before the bombings. Dzhokhar Tsarnaev later became a U.S. citizen.

Their path to radicalization bears some resemblance to European cases, in which young men joined the Islamic State of Iraq and the Levant (ISIL) after expressing interest in anti-U.S. ideology or in the propaganda of those sympathetic to Al-Qaeda and similar groups. 

Years before the Boston Marathon attack, the brothers befriended a brain-damaged man named Donald Larking, a patient of their mother, who worked as a health care aid. Larking was an anti-U.S.-government conspiracy theorist and had discussed his ideas with the Tsarnaev brothers, according to attorney Jason Rosenberg, who represents Larking's family.

On Wednesday, FBI Special Agent Christopher Derks identified various items belonging to Dzhokhar Tsarnaev in the apartment. He said agents found a book with two sheets of loose-leaf paper inside with handwritten notes, including the name Tarek Mehanna, a Sudbury, Massachusetts, man who was convicted in 2012 of conspiring to help Al-Qaeda, and a reference to Anwar al-Awlaki, an American-born Muslim cleric and Al-Qaeda propagandist who was killed in a U.S. drone strike in Yemen in 2011. Derks did not say whose handwriting it was.

In the federal indictment against Tsarnaev Tsarnaev, which was released in June 2014, authorities alleged they found on his computer a publication written by someone known as the “Father of Global Jihad” that advocates violence against the perceived enemies of Islam.

Prosecutors also alleged that Dzhokhar Tsarnaev downloaded a publication that "glorifies martyrdom in the service of violent jihad" and an Al-Qaeda magazine that had directions for building bombs using pressure cookers.

Al Jazeera and The Associated Press