Dzhokhar Tsarnaev was flunking school ahead of Boston bombing, trial hears

Jurors in the trial of Boston Marathon bomber Dzhokhar Tsarnaev were shown the white cap that helped authorities identify him as a suspect in the 2013 deadly attack.

During testimony at his federal death penalty trial on Tuesday, jurors were shown items found in his dorm room at the University of Massachusetts-Dartmouth. The white cap was found on Tsarnaev's bed.

• Tsarnaev trial hears blood, DNA evidence related to police shootout
• Boston bombing trial witnesses say blast like 'a horror movie'
• Dzhokhar Tsarnaev ID'd by witness as man near slain officer's car

The FBI referred to Tsarnaev as "White Hat" until they were able to identify him. Photos and surveillance videos of Tsarnaev wearing the cap backwards were released by the FBI three days after the bombings when they asked for the public's help in identifying the suspects Tsarnaev and his older brother, Tamerlan.

The hat was a Ralph Lauren Polo with the figure of a man on a horse on the front and the number `3' on the side.

Tsarnaev's lawyers admitted during their opening statement that Tsarnaev participated in the bombings, but said Tamerlan was the mastermind. Tamerlan, 26, died four days after the bombings following a gun battle with police.

Failing courses leading up to bombing

Also on Tuesday, jurors were shown a note that Tsarnaev wrote to college officials three months before the bombings in which he attributed his poor grades to losing "too many" loved ones in Chechnya.

Tsarnaev, then in his sophomore year, wrote that his relatives live in Chechnya, which he described as a republic "that is occupied by Russian soldiers that falsely accuse and abduct innocent men under false pretenses and terrorist accusations."

Tsarnaev said he was now at the point where he could focus on his school work.

"I wish to do well so one day I can help out those in need in my country, especially my family members," he wrote.

Tsarnaev, then 19, did not identify the family members or give any other information.

Mark Preble, the chief financial officer of UMass-Dartmouth, said Tsarnaev's appeal to restore his financial aid was denied after he submitted his explanation.

The jury also was shown a transcript of Tsarnaev's grades. He received three Fs and one B during the fall 2012 semester, the months before the bombing.

Three people were killed and more than 260 were injured when twin bombs went off near the finish line of the marathon on April 15, 2013.