VISTA, Calif. -- The penalty phase of a trial is scheduled to begin Monday for a man convicted of first-degree murder in the September 2005 stabbing death of a young mother who interrupted him during a burglary of her Vista home.

Jurors will be asked to recommend the death penalty or life in prison without parole for Derlyn Ray Threats, a 28-year-old former Camp Pendleton Marine convicted in the slaying of 24-year-old Carolyn Neville.

The jury deliberated over four days at the Vista Courthouse before convicting Threats of first-degree murder, robbery and burglary, and finding true three special circumstance allegations -- murder during a robbery, murder during a burglary and murder by torture.

In his closing argument, Deputy District Attorney Patrick Espinoza told the jury the evidence was overwhelming that Threats killed Neville on the morning of Sept. 1, 2005.

The day Neville was slain started out with her dropping off her 6-year- old son at school and returning home to do chores, Espinoza said. Because she had misplaced her house keys, the front door to the home had been left open, according to the prosecutor.

Neville had gone upstairs when she was attacked by Threats and pursued throughout her home.

"She wanted to get away. She wanted to live another day." Espinoza told jurors. "And you know she was fighting for her life."

Though injured, Neville was able to get outside, but Threats pulled her back in the house, locked the door and continued to attack her for 20 minutes, Espinoza said.

Neville had 70 separate wounds, including 47 to her head, face and neck, the prosecutor said. Most of the injuries were inflicted while the victim was alive, a medical examiner investigator testified.

Espinoza called the killing "sadistic -- just a level of horror (with) unspeakable acts."

Thanks to quick work by sheriff's deputies, Threats was caught a short distance away, hunkered down by a nearby home, the prosecutor said. He said the victim's blood was splattered on Threats' clothing, providing "damning, compelling evidence of guilt."

Neighbors said they'd seen Threats earlier in the morning casing the neighborhood looking for homes where, according to authorities, he could steal video games.

The night before the killing, a friend of the defendant said, Threats was up all night playing video games. Once Threats killed Neville, he went back to loading video games into a suitcase he had taken from her laundry area, the prosecutor said.

Defense attorney James Weintre, in his closing argument, told the jury that a neighbor named "Tony" was the real killer. He said Threats was a peaceful and non-violent person who couldn't have committed the murder.

Espinoza said the defense tried to pin the murder on "Tony" because he is African-American, as is Threats. Investigators determined that "Tony" was sleeping when Neville was attacked and killed, the prosecutor said.