PHOENIX - Jodi Arias spent 18 days on the stand sharing emotional and oftentimes X-rated details of her life before a rapt television and online audience. She had hoped it all might convince a jury that she killed her onetime boyfriend in self-defense.

But the eight men and four women on the panel didn't buy it, convicting Arias of first-degree murder after about 15 hours of deliberations. Jurors will return Thursday to begin the next phase of the trial that could set the stage for Arias' receiving a death sentence - a penalty she said she now desires in a stunning interview after her conviction.

Arias talked to Fox affiliate KSAZ in the courthouse minutes after she was convicted. With tears in her eyes, she said she was overwhelmed and surprised because she did not believe she committed first-degree murder.

"It was unexpected for me, yes, because there was no premeditation on my part," she said.

Arias also told the station that she would "prefer to die sooner than later" and that "death is the ultimate freedom."

When asked about Travis Alexander's family, Arias said: "I just hope that now that a verdict has been rendered, that they'll be able to find peace."

The case elevated the waitress and aspiring photographer to a household name. The crime itself was enough to grab headlines: Arias, 32, a high school dropout, shot Alexander in the forehead, stabbed him nearly 30 times, and slit his throat from ear to ear, leaving the motivational speaker and businessman nearly decapitated.

She said he attacked her and she fought for her life. Prosecutors said she killed out of jealous rage after Alexander wanted to end their affair and planned to take a trip to Mexico with another woman.

The Maricopa County Sheriff's Office said Arias contacted KSAZ on Sunday, telling the reporter she would honor a previous promise to speak on camera if the verdict was first-degree murder.

She was placed on suicide watch afterward, the office said.

Arias fought back tears as the verdict was announced Wednesday in the hushed courtroom, while Alexander's family members wept and hugged one another. They wore blue ribbons and wristbands with the words Justice for Travis.

Outside, a huge crowd that had gathered on the courthouse steps cheered the news.

Arias' mother, Sandra, declined to comment.

Testimony began in early January. The trial quickly snowballed into a made-for-the-tabloids drama, garnering daily coverage from cable news networks and spawning a virtual cottage industry for talk shows, legal experts, and even Arias, who used her notoriety to sell artwork she made in jail.

Jurors got the case Friday afternoon.

The trial now moves into the so-called aggravation phase, during which prosecutors will argue the 2008 killing was committed in an especially cruel, heinous, and depraved manner that should allow jurors to consider the death penalty. Both sides may call witnesses and show evidence. If the panel finds the aggravating factors exist, the trial then moves into the final penalty phase, during which jurors will recommend either life in prison or death.