SAN DIEGO -- A man who was 17 years old when he shot a woman in the back during a robbery near her City Heights apartment more than 15 years ago was convicted Tuesday of first-degree murder.

Khary Watson, 32, faces life in prison without the possibility of parole when he is sentenced Dec. 18 by Judge Kerry Wells.

After deliberating over parts of three days, jurors found the defendant guilty of murdering 54-year-old Patricia Lopez and found true a special circumstance allegation that the murder happened during a robbery.

Watson looked back at the audience in the courtroom and shook his head after the verdicts were read.

Deputy District Attorney Clay Biddle said in his opening statement that both Watson and co-defendant Tyrone Katrel Lynch made incriminating statements after their arrests last year, linking them to the Oct. 1, 1994, robbery and murder.

Watson's first trial began in late September but ended a few days later when his attorney, Thomas Ochs, became too sick to come to court.

Biddle said Watson told Lynch shortly after their arrests that he shot Lopez "because she bit me."

In a holding cell, Lynch told Watson, "Not everybody should have to go down for this," to which the defendant responded, "It's already too late," according to Biddle.

Later, an agitated Lynch asked Watson, "Why couldn't you just shoot her in the leg or something?", Biddle told the jury.

The prosecutor said Lopez -- a mother of four -- was gunned down as she and friend Barbara Nickerson returned to the victim's apartment about 10 p.m. after a walk to a nearby liquor store for cigarettes.

Biddle said Watson came up behind Nickerson and stuck a gun in her back.

The gunman ordered Nickerson to drop her fanny pack to the ground, and when she did, Lopez took off running toward her apartment on 55th Street, Biddle said.

Watson, who was 17 at the time, caught Lopez on a nearby lawn and shot her once in the back, perforating her heart, the prosecutor said.

Nickerson had 20 cents in her fanny pack and Lopez had 76 cents on her, Biddle said.

Following the shooting, Watson and Lynch fled to a waiting car driven by a woman named Komoa Greene, the prosecutor said.

The killing went unsolved until November 2006, when a man called police and told them about a woman involved in the killing of an Hispanic woman in San Diego 12 years earlier, Biddle said.

A 25-caliber gun was traced to Greene, and she admitted involvement in the robbery that led to Lopez's murder, Biddle said.

Lynch and Greene subsequently pleaded guilty to voluntary manslaughter and Lynch testified against Watson.

Ochs told the jury the murder weapon was never recovered and there was no physical evidence linking his client to the murder.

Ochs said Watson was outside the circle of individuals who committed robberies and a homicide that night.

The attorney said witnesses who initially identified Watson as the person who robbed them weren't sure of their identification.