Arias, wearing a silky, cream-colored blouse, appeared to fight back tears most of the morning but showed little emotion when the decision was announced. Afterward she chatted with her attorneys.
Arias spent the weekend on suicide watch before being transferred back to an all-female jail where she will remain until sentencing.
Martinez told jurors Wednesday that Alexander "suffered immensely" at Arias' hands.
"She made sure she killed him by stabbing him over and over and over again," he said.
The defense didn't have much of a case given how many times Alexander was stabbed, the defensive wounds on his hands, the length of the attack, and the sheer amount of blood found at the scene. Defense lawyers said Alexander would have had so much adrenaline rushing through his body that he might not have felt much pain.
The only witness was the medical examiner who performed the autopsy and explained to jurors how Alexander did not die calmly and fought for his life as evidenced by the numerous defensive wounds on his body.
Minutes after her first-degree murder conviction last Wednesday, Arias granted an interview to Fox affiliate KSAZ, only adding to the circus-like environment surrounding the trial that has become a cable TV sensation with its graphic tales of sex, lies and violence.
"Longevity runs in my family, and I don't want to spend the rest of my natural life in one place," a tearful Arias said. "I believe death is the ultimate freedom, and I'd rather have my freedom as soon as I can get it."
However, Arias cannot choose the death penalty. It's up to the jury to recommend a sentence.
The medical examiner who performed the autopsy testified Wednesday that Alexander did not die calmly and fought for his life as evidenced by the numerous defensive wounds on his body.