A jury that had found a San Jose man guilty of slaying his girlfriend in an argument over a Louis Vuitton handbag concluded Thursday he was sane when he committed the murder, a Santa Clara County deputy district attorney said.

Jurors rejected defendant Peter Shui's claim that he was insane when he stabbed 33-year-old Lijia Zheng 11 times with a kitchen knife in her San Jose apartment on Aug. 4, 2011, Deputy District Attorney Erin West said.

The same jury found Shui, 50, guilty of second-degree murder on Wednesday when it could have opted for first-degree murder, as West argued, or involuntary manslaughter, as requested by the defense, West said.

After the jury's first verdict Wednesday, the trial entered a one-day sanity phase today when jurors heard from two doctors as witnesses for the prosecution and one doctor called to make Shui's case, West said.

"(Shui) said he was literally mentally ill" when he stabbed Zheng, West said.

Shui's defense tried to persuade the jury that Shui "suffered from psychosis" and that Shui told a doctor that the victim's "face transformed into the face of the devil" prior to the stabbing, West said.

"The doctors I brought in did not believe he was truthful," West said.

A piece of evidence that hurt Shui's defense during the two-week trial was a recording of his voice in a 911 emergency call he placed after the stabbing, West said.

On the recording, Shui told the emergency dispatcher that he injured Zheng "so many times because she kept yelling at me."

"That's what the (prosecution's) doctors really based their opinions on, that he knew what he was doing, that he really wasn't crazy," West said.

Shui also tried to argue that he stabbed Zheng, a Chinese national, because he was intoxicated, but jurors did not take that into account based on what they said outside the courtroom today, West said.

Prior to the murder, Shui, who was married, unemployed and earning money playing the Chinese tile game mahjong, carried on an affair with Zheng and his wife knew about it, West said.

On Aug. 3, 2011, Shui's wife spotted Zheng at a local mall and noticed Zheng carrying an expensive Louis Vuitton handbag.

  His wife confronted him later that day about why his lover had the handbag, West said.

The next day, Shui informed Zheng about his wife's discovery of the bag, to which Zheng replied that Shui did not even buy the bag for her.

As the couple argued, Shui grabbed an 8-inch kitchen knife and stabbed Zheng to death, West said.

West described the murder as "a classic domestic violence rage killing."

Shui faces a penalty of 15 years to life imprisonment at a sentencing hearing set for April 26, West said.