Prosecutor Juan Martinez showed a photo of Arias' ex-boyfriend Travis Alexander's throat slit within minutes of starting to make his case, saying. "This is how much she loved him."
And Martinez ended his opening statement by telling the jury, "The only just punishment in this case is death."
The Maricopa County Superior Court in Arizona was filled with supporters on either side, including Alexander's siblings on one side of the room and Arias' parents and brother on the other.
Arias, now 34, was found guilty of murder last year by a jury that rejected her argument that she shot Alexander, stabbed him numerous times and slit his throat in self defense. But the first jury was unable to agree on whether Arias should be condemned to death.
The current jury of 12 women and six men -- which includes six alternates -- will be asked to decide whether Arias is executed.
"It is up to you to write the final chapter of this story," said Nurmi, a state-appointed defense attorney who represented Arias throughout the nearly six month trial last year.
Nurmi dedicated much of his nearly 45 minute opening statement issuing warnings to the jury, warning that there will be graphic evidence including autopsy photos, sexually explicit photos, and transcriptions of the X-rated text messages that Arias exchanged with Alexander in the months before his June 2008 murder.
Nurmi stressed how Arias had no prior criminal history, suffered alleged physical and emotional abuse at the hands of her parents, and then allegedly experienced more emotional and physical abuse from Alexander, a Mormon motivational speaker.
The lawyer characterized her relationship with Alexander as "one of lust, passion, forbidden sex."
The original trial included a flood of explicit descriptions about their sexual encounters. The murder trial was live streamed, but the current judge has allowed a camera to be in the courtroom, but ordered that no footage of the proceedings can be released after the sentence is handed down.
Much of the evidence brought up in the original trial is expected to be raised once more, largely by the prosecution who will try to convince the jury that her actions before Alexander's death indicate the killing was premeditated rather than a crime committed in the heat of the moment.
Martinez started this effort today, telling the jury about how she bought gas out of state to allegedly avoid a credit card trail at gas stations close to Alexander's house.
He also showed photos of the crime scene retrieved from Arias' camera that police found in Alexander's laundry machine.
The court estimates that the sentencing trial could take two months.