Discuss as:

Jodi Arias should die, victim's brother and sister tell Phoenix jury

The jury took only three hours Wednesday to decide that Jodi Arias was guilty of premeditated murder with aggravating circumstances. Her legal team is now fighting to prove she doesn't deserve the death penalty. NBC's Diana Alvear reports.

In tear-filled statements, the brother and sister of the man Jodi Arias was convicted of murdering told jurors Thursday that his brutal killing had ripped the heart out of the family.

Jurors were hearing arguments over whether Arias deserves to die for killing Travis Alexander in 2008. The same jurors found Wednesday that she had been "especially cruel" in his slaying, which could justify the death penalty under Arizona law.

"Travis was our strength, our constant beacon of hope, our motivation, and his presence has been ripped from our lives," Samantha Alexander, a police officer and one of Alexander's seven brothers and sisters, said in a 15-minute statement, during which she repeatedly had to stop to choke back tears.

Steven Alexander said he continues to suffer nightmares since his brother's death.

"I've had dreams of my brother curled up in the shower, groaning and left to wait for days," he said. "I don't want to have to see my brother's murderer anymore."

Arias, 29 — who stabbed Alexander 27 times, slashed his throat and shot him after he was already dead, all of which she said she did in self-defense — put her hand to her mouth and appeared to wipe away tears as Alexander's siblings struggled their way through the victim impact statements.

Arias' lead attorney, Kirk Nurmi, told the jurors that they could no longer consider the issue of whether to sentence her to die a "hypothetical," because "she's right here. This is the girl right here."

Nurmi reminded jurors that they had pledged to "consider giving life" even if they found aggravating circumstances.

"That is what you committed to do, and ladies and gentlemen, that is what we expect you to do," he said.

Watch US News crime videos on NBCNews.com