A Palo Alto woman who was charged with murder for allegedly stabbing her sister-in-law 41 times reached a plea deal last week and has been released from jail.

Jingyan Jin, 46, was set to stand trial for the 2016 murder of Jenny Shi in her Palo Alto home. Opening statements were scheduled to begin Tuesday, but Jin instead reached a deal with prosecutors and pleaded no contest to involuntary manslaughter.

According to Deputy Public Defender Rebecca Kahan, Jin maintains her innocence, but took the plea deal because it was a guarantee she would be released from jail.

"She's innocent and yet she's facing 25 years to life in state prison," Kahan said. "So after five years in jail, she pled to ensure that there was no risk of further jail time."

The involuntary manslaughter charge carries a maximum sentence of four years, but because Jin had already been held in jail for nearly five years, she was immediately eligible to be released.

The plea deal came after problems emerged with key pieces of the prosecution's evidence. To proceed, prosecutors would have had to dismiss the case, reevaluate their evidence and then refile charges, Santa Clara County Deputy District Attorney Carlos Vega said.

"That put us in a different posture, and ultimately a resolution was reached in this case with defense counsel," Vega said.

Kahan characterized cellphone data in the case as "completely unreliable" and said DNA evidence was potentially going to be excluded.

"What occurred in this case is that, to the prosecutor's credit, he ultimately realized that critical forensic evidence was faulty and could not be presented to a jury," Kahan said.

The trial stemmed from the brutal killing of Shi, an acupuncturist and angel investor, in her Creekside Drive home in the Greenmeadow neighborhood. Shi, 65, was found lying dead in her bed on the evening of July 7, 2016. Investigators determined that an intruder had entered the residence in the early morning hours of July 7 through the window of a bathroom that connected to the master bedroom, Vega said.

Jin, the wife of Shi's brother, was arrested in October 2016 and charged with murder. According to Vega, Jin and Shi had a history of disagreements. In particular, Vega said there was possible evidence that Jin's husband had been putting property in his sister's name in an effort to retain the property in the event he and Jin got divorced.

"There was definitely bad blood between the victim and the defendant," Vega said. "They were not on good terms."

Kahan pushed back on this framing of the case, saying that "just because the prosecution planned to go with that motive, doesn't mean it's true."

"It is unfortunate that past articles repeated unfounded gossip as though it were fact," Kahan said.

Lawyers had been in the process of picking a jury in the case and conducting evidentiary hearings when it became clear that an analysis of cellphone location data placing Jin in the vicinity of Shi's house during the time of the crime was "faulty," Vega said. The cellphone site list from AT&T that an expert had used wasn't complete, Vega said.

Two out of three pieces of DNA evidence also appeared likely to be excluded, he added.

"It is misleading to claim that DNA linked her to the crime scene," Kahan said. "That statement ignores proven research about DNA transfer and the complexities inherent in DNA mixtures."

All told, the prosecution was facing the prospect of dismissing the case and then refiling. Instead, they offered a plea deal.

"It was a circumstantial case to begin with," Vega said. "All of these things holistically led us to this decision."