Arias, 32, faces either a life sentence or the death penalty for the murder of Travis Alexander.
Samantha Alexander, the victim's sister, told the jury that her and her family's lives had been changed forever and that in her 11-year career with law enforcement she had never seen images as gruesome as the ones of her slain brother.
"Our minds are currently stained with the images of our poor brother's throat slit from ear to ear," she said sobbing.
Steven Alexander, the victim's brother, confessed he'll never forget the night he learned about his brother's death recalling that the last time he saw him was the day Travis met his daughter. He added that his brother had left a legacy and that it was their job to make sure it survived.
"You were born to be great, it is your destiny," he said citing his brother. "The difference between a stumbling block and stepping stones is the character walking the path."
Kirk Nurmi, an attorney for Arias, also spoke to the jury and reminded them that they hold Arias's life in their hands as the verdict they choose will be binding.
"Make no doubt about it, as the judge said to you moments ago, the verdict you will render is not a recommendation," Nurmi said. "The judge is not free to disregard it...if you sentence her to death, she will stand at this podium and be sentenced by the judge to death."
The second phase of the trial will resume Friday at 10 a.m. where the jury will hear more testimony.