After just two days of testimony in the Boston Marathon bombing trial, defense lawyers representing accused bomber Dzhokhar Tsarnaev rested their case on Tuesday.

The 21-year-old suspected terrorist is currently standing trial for his role in the Boston Marathon attack, which killed three people and injured 264 others on April 15, 2013. Although Tsarnaev, 21, has confessed to the crime, his lawyers reiterated their argument that he participated in the bombing when he was 19 years old because he was under the influenced of his older brother, Tamerlan, 26. Their goal is to save Tsarnaev, who is facing 30 federal charges, from the death penalty, reports The New York Times.

Calling only four witnesses to the stand, the defense presented their case that Tamerlan, who was killed three days after the bombing, was the mastermind behind the terror attack and took all the major steps to carry it out.

On Tuesday, an FBI agent testified that investigators only found Tamerlan's fingerprints on bomb pieces from the two pressure cooker bombs used in the attack. The deceased brother's prints were also found on materials used to plan and carry out the bombings.

In addition, the defense called computer forensic analyst Mark Spencer to the stand, who said that he found Internet searches for the Boston Marathon, gun stores, wireless transmitters, detonators and a "fireworks firing system" on a laptop the defense claims was owned by Tamerlan, reports NBC News. Meanwhile, there were no such searches on Dzhokhar's device, except for a search for the marathon after the bombings, Spencer said,.

Spencer also noted that copies from an al Qaeda-associated magazine were created on Tamerlan's computer before being transferred to Dzhokhar's.

However, while being cross-examined, Spencer admitted that it was impossible to know who was using either of the laptops at any time. Prosecutors also pointed out that different fingerprints can easily be destroyed in an explosion.

Closing arguments are scheduled for Monday, April 6.