Defense lawyers in the Boston Marathon bombing trial pleaded with the jury to spare the life of client Dzhokhar Tsarnaev, who they described as "a good kid" under the influence of his radicalized older brother.

Earlier this month, the 21-year-old convicted terrorist was found guilty of 30 charges for his role in the 2013 Boston Marathon bombings, including conspiracy to use a weapon of mass destruction and bombing a public place. The charges also covered a carjacking that took place in the aftermath of the attack, the deadly shooting of a Massachusetts Institute of Technology police officer, and a gunfight in Watertown, Massachusetts, in which Tsarnaev and his now-deceased brother tossed explosives at police.

During the original trial, the defense team argued that Tsarnaev participated in the attack that killed three people and injured over 260 others on April 15, 2013, because he was being influenced by his brother, Tamerlan. Now, it is up to the same jury to decide whether Tsarneav should face life in prison or death.

According to the defense, there is no punishment for Tsarnaev that could come close to the suffering that he caused the victims of the bombing attack.

"There is no evening the scales. There is no point in trying to hurt him as he hurt because it can't be done," said attorney David Bruck in his opening statement of the penalty phase on Monday, reports USA Today.

Bruck added that although Tsarnaev was not forced to commit such horrendous acts of violence, the jury should spare his life and sentence him to life in prison.

"He will be securely locked away where he can never hurt anyone," Bruck said whiles showing the jury a photo of the federal ADX Florence supermax prison in Colorado. "He goes here and he's forgotten. No more spotlight like the death penalty brings. His legal case will be over for good, and no martyrdom."

Tsarnaev "was a good kid," Bruck said at one point. "Dzhokhar really was what he appeared to be -- a lost teenager."

Tsarnaev's lawyers also revealed that Tamerlan planned a terror attack in Russia in 2012, but instead returned to the United States and "pulled his younger brother in" his plot to detonate two pressure cooker bombs at the race.

"In January 2012, Tamerlan left his family to go to Russia and 'go into the forest' to join radical jihadi fighters. He had been planning to wage jihad in Russia. He told people he had gone overseas to die, but returned because he said he could not find a holy war," Bruck told the jury, reports the Los Angeles Times.

Back in Boston, Bruck said that "Tamerlan had power over the Islamic Society of Boston, in Cambridge. Tamerlan interrupted Friday service, screaming and yelling at the imam in the middle of the sermon. Tamerlan got to the point where he [believed he] knew what was sure and everyone else did not. He was picking fights with people about religion. He was aggressive and extreme, and walking around dressed in flowing white robes like a Muslim sheik."

The lawyer added that "We will describe how Tamerlan was a very tough guy, a boxer. He was suspended from high school and arrested for assaulting a fellow student, and he assaulted his girlfriend."