Photo of Tsarnaev giving middle finger in cell shown at trial

BOSTON — During a dramatic first day of the penalty phase in the trial of Dzhokhar Tsarnaev, federal prosecutors showed the jury an image of the convicted Boston Marathon bomber giving the middle finger to a security camera at the courthouse.

The photo — long rumored but seen for the first time in court Tuesday — was captured as Tsaranev was waiting to be arraigned on bombing charges in July 2013. Dressed in an orange prison jumpsuit with his face visibly scarred, Tsarnaev appears furious as he gestures to the camera.

It was a sharp contrast to Tsarnaev's demeanor in court, where he has offered little reaction or emotion to even the most gut-wrenching of testimony since his trial began.

"This is Dzhokhar Tsarnaev," prosecutor Nadine Pellegrini said. "Unconcerned, unrepentant and unchanged."

It was not clear if the photo would be made public. The photo was not formally entered into evidence, and prosecutors did not say whether the video it was taken from would eventually be shown in court.

Tsarnaev, 21, was convicted this month of all 30 charges related to the April 15, 2013, bombings that killed three and injured nearly 300 at the marathon. The jury is now considering whether he will receives life in prison or the death penalty for his role in the attacks.

Tsarnaev’s attorneys admitted their client participated in the attack, but are expected to argue that he was a troubled teenager who came under the sway of his radicalized older brother, Tamerlan, who they have said was the mastermind of the terror plot. Tamerlan Tsarnaev was killed in a shootout with police four days after the bombings when his brother ran him over with a car while fleeing police.

But as they have throughout the case, prosecutors argued Tuesday that Tsarnaev was an equal partner in planning and carrying out the attacks. Pellegrini labeled him a cold-blooded killer who was "determined and destined to be America's worst nightmare."

[Live coverage: The trial of Boston Marathon bomber Dzhokhar Tsarnaev]

She repeatedly called him as a "willing" participant in the plot who was "callous and indifferent" to human life.

"You may hear about family dynamics, family history, family dysfunction," Pellegrini said. "But many people — millions of people, I would venture — face troubles throughout their lives. Who among them murders people with a bomb?"

Prosecutors have rejected defense attempts for a plea deal in the case, even though many of the bombing victims — and a majority of Bostonians — support a life sentence without parole.

They include the parents of 8-year-old Martin Richard — the youngest victim of the attacks —who asked prosecutors last week to “end the anguish” of the trial, and likely years of appeals, by taking the death penalty off the table.

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— With Dylan Stableford contributing reporting.