Washington, April 22 (IANS): The penalty phase in the trial of Boston Marathon bomber Dzhokhar "Jahar" Tsarnaev began on Tuesday, less than two weeks after he was convicted on all 30 counts related to the blasts in 2013.

Federal prosecutor Nadine Pellegrini introduced a new photo on Tuesday, which showed Tsarnaev giving his middle finger to a security camera in his prison cell three months after the attack, according to a Xinhua report.

Pellegrini said that it proved what kind of a person the 21-year-old Tsarnaev was and why he should get the death penalty.

"Jahar Tsarnaev was and is unrepentant, uncaring and untouched by the havoc and sorrow that he has created," Pellegrini said in a Boston court. "He was willing to cross every line for glory and reward."

Tsarnaev was convicted earlier this month on all 30 charges against him during the trial's guilty-or-innocence phase.

On Tuesday, the same jury began the final phase of the trial to figure out whether Tsarnaev should get the death penalty or be sentenced to life imprisonment.

Pellegrini's presentation was followed by victims' impact statement starting with Celeste Corcoran, who made her way to the stand on two artificial limbs. She was waiting for her sister by the marathon finish line when the bombs went off within 12 seconds of one another.

"I remember hearing just blood-curdling screams. I just remember looking around and seeing blood everywhere," Corcoran said.

"I just remember thinking how awful this was and how this had to stop. This couldn't be real, couldn't be real," she added.

Tsarnaev's lawyers, who will put forward the case for mercy are expected to portray Tsarnaev's brother Tamerlan as the mastermind of the bombing.

They have said that Tsarnaev was a 19-year-old who fell under the evil influence of his domineering brother, who died in a confrontation with police after the bombing.

However, prosecutors have contended that Tsarnaev was a full partner in the crime and deserves the ultimate punishment.

"Jahar Tsarnaev was determined and destined to be America's worst nightmare," Pellegrini said, adding, "His heart was full of rage."

On April 15, 2013, two bombs went off near the finish line of the Boston Marathon, killing three people and wounded more than 260.

Dzhokhar Tarnaev and his 26-year-old brother Tamerlan Tsarnaeve were alledgedly behind the deadly bombing.