A Palo Alto mother of two will face first-degree murder charges in the July stabbing death of her sister-in-law, the Santa Clara County District Attorney's office announced on Tuesday, Oct. 11.

Jingyan Jin, 41, is accused of stabbing 65-year-old acupuncturist Jenny Shi 41 times in Shi's bedroom on July 7, according to a Palo Alto Police Department statement of facts. Shi, a successful but very private businesswoman and angel investor, was found lifeless at her home on the 300 block of Creekside Drive of the Greenmeadow neighborhood by her sister, who called police at about 7:45 p.m.

Shi had missed a 10 a.m. business appointment that day and had not been heard from since the night before, according to the police statement by Detective Eric Bulatao. A business associate and a bookkeeper went to Shi's home to check on her. The front door was locked and Shi's car was still parked in the driveway. The business associate called Shi's maid to bring a key to open the door.

The maid arrived, accompanied by her husband. A contractor and Shi's sister, Yanne Shi, arrived at the house separately. All four entered the residence, but the bedroom door was locked, according to the report. The contractor broke through the door, but there was a second door behind it, which was also locked. That door had to be removed from its hinges.

Shi's sister entered the bedroom and found Shi on the bed in a large amount of blood. All four left the residence and called police.

A number of expensive items, located in plain sight, had not been taken, but Bulatao found a chair propped against a window frame outside of the home. The ground showed marks in the dirt made by dragging the chair to the window. The window screen had been cut on three sides and a small window removed; it was found laying in the bathtub, according to the report.

Jin was identified by the Santa Clara County Crime Lab in late September by partial DNA evidence found on the window knob and on the edges of the same window, according to the report.

Jin allegedly had a rocky relationship with Shi, according to a neighbor of the victim. Jin had lived in the home with her two children for a time, but she moved out about a year ago because the two women were not getting along, the neighbor said.

Police also said that Jin, who is married to Shi's brother, had allegedly threatened her husband with a knife and a stun gun, allegedly drugged a cup of his tea with Benadryl and had a verbal altercation with Shi at the home within the past year.

Jin was also arrested in China in September for allegedly fighting with one of Shi's business employees after having attempted to enter the employee's apartment while possessing a knife and plastic gloves, according to the report.

Police waited for Jin to return to Palo Alto from China and they arrested her near her home in the 700 block of San Antonio Road, Deputy District Attorney Christopher Walsh said. The DNA and her relationship with Shi will weigh significantly as evidence, he said.

"This is a case that fortunately has been solved. Had this case taken place 20 or 30 years ago this is a case that might not have been solved. There were numerous initial suspects that were looked into, but ultimately what solved this case was forensic science and DNA, and that evidence led back to this defendant," he said.

Walsh said Shi was likely killed in the 24 hours prior to being found. Prosecutors and police have some ideas on the motive, but Walsh said he doesn't want to speculate because the investigation is ongoing.

"I do think that the facts -- as the case proceeds forward and this information comes to light -- I believe the motive will be very clear and also the location of the DNA will be very significant as a piece of evidence in this case.

"I think you'll see there is a past history that goes to the relationship, which is significant evidence in this case," he said.

On Tuesday, the diminutive Jin sat in the courtroom composed and alert in a red jail uniform, waving cheerfully at three friends who had come to the court proceeding.

The friends, who asked not to be named, said Jin's two children attend school with their children.

"We can't believe that she would be accused of something like this. She is just a mother of two children. She is a very nice person. We just care about her," one of the women said.

"I'm shocked," said another woman who described Jin as "a lovely person."

She said that Jin regularly volunteered at the school. She recalled going to Shi's house a few times when Jin and her children lived there. She took part in a Bible-study group at the home with Jin.

But "something happened about two years ago," the friend said, although she did not know the nature of the disagreement. Shi also reportedly told Jin not to have the Bible group at the home anymore, she said.

Jin's arraignment in Santa Clara County Superior Court was postponed until Wednesday because a Mandarin-speaking translator was not available. Jin remains in custody without bail.