PHOENIX — An Arizona jury found Jodi Arias guilty on Wednesday of first-degree murder in the death of her ex-boyfriend in a capital trial that riveted America for months with graphic sexual evidence and bizarre testimony.

Arias, who could face the death penalty as her case goes into the penalty phase of the trial, has admitted to shooting 30-year-old Travis Alexander, whose body was found in the shower of his Phoenix valley home in June 2008. He had been shot in the face, stabbed multiple times and his throat had been slashed.

Arias, 32, had said she acted in self-defense after Alexander attacked her because she had dropped his camera while taking photos of him in the shower.

Arias teared up as the jury’s decision was read, while a crowd erupted into cheers outside the court following the verdict.

The trial, which began in early January and was punctuated by graphic testimony and evidence including a sex tape, was streamed live on the Internet and drew widespread media attention.

Jurors heard how the petite, dark-haired Arias met and began dating Alexander, a businessman and motivational speaker, in 2006. During 18 days of often gripping and salacious testimony, Arias said that she and Alexander continued to have sex despite their break-up from a relationship that was marked by emotional and physical abuse.

Arias said Alexander had made her feel “like a prostitute” and that he kicked and attempted to choke her, although she admitted never reporting the alleged abuse to the police, seeking medical treatment or documenting it in her journal.

Defense attorney Kirk Nurmi said Arias had snapped in the “sudden heat of passion” in the moments between a final photograph she took showing Alexander alive and taking a shower and a subsequent picture showing him covered in his own blood.

Described as manipulative

But prosecutor Juan Martinez painted a different picture of Arias, portraying her as manipulative and prone to jealousy in previous relationships, and said she had meticulously planned to kill Alexander.

“Nothing indicates that this is anything less than a slaughter,” he told jurors in his summing up on Friday, asking them to return a verdict of felony first-degree murder.

Martinez accused Arias of bringing the pistol used in the killing, which has not been recovered, with her from California, and said she rented a car, removed its license plate and bought gasoline cans and fuel to conceal her journey to the Phoenix suburbs to kill Alexander.

Martinez said Arias had lied after the killing to deflect any suspicion that she had been involved in his death, leaving a voicemail on Alexander’s cellphone, sending irises to his grandmother and telling detectives she was not at the crime scene before changing her story.

The jury grilled her on her claims that her mind went blank after she shot Alexander, and wanted to know why she had not called emergency responders — questions she struggled to answer.

The defense called a psychologist who testified that Arias’ memory lapses stemmed from post-traumatic stress as a result of Alexander’s alleged abuse and the killing itself — claims disputed by prosecutors.

In closing arguments, Martinez told the jury Alexander had sent an instant message weeks before his death saying he was “extremely afraid” of Arias because of her “stalking behavior.”

Reporting by Tim Gaynor; editing by Cynthia Johnston, David Brunnstrom, Richard Chang and Peter Cooney.