Attempted murder case nears end with poisoning plea deal

A man who was charged with trying to kill a colleague at a Berkeley engineering firm by putting a toxic metal in her water has been placed on probation after being convicted of poisoning, court records show.

Berkeley police originally arrested David Xu at his Lafayette home in 2019. He was subsequently charged with attempted murder as well as two counts of poisoning.

The victim used a spy camera in her office to catch Xu in the act, police said at the time.

Since then, the case has crawled through the court system at a glacial pace, with Xu out of custody on house arrest with an ankle monitor for part of that time.

New court records, which shed light on what happened, became available in recent weeks after Xu was sentenced in mid-March.

Neither Xu nor his victims addressed the court during the sentencing hearing.

But, in a written statement, the victim said she initially thought she had "a late-stage cancer and could die at any time" after being poisoned for more than a year.

"My health deteriorated due to poisoning from 2017 to 2019 and has worsened since," she wrote in October 2023. "I frequently experience lightheadedness, pain in the liver area, and had a heart attack this January."

Suspect told victim air quality or mold might have caused her symptoms

The woman began experiencing various forms of stomach upset in October 2017 that continued "sporadically but repeatedly" until February 2019, prosecutor Gregory Dolge wrote in his own memo to the court last year.

She had started working at the engineering firm with Xu in early 2017.

The woman eventually determined that she was having symptoms after drinking from her water bottle at work.

Tests for food allergies and other medical issues all came back negative.

In November 2018, Dolge wrote, David Xu expressed "alleged concern for the victim, and suggested that it was perhaps an air quality issue or mold in the company building. He also asked her if doctors had found anything from her blood and urine tests."

In November and December 2018, the woman's mother used water from her bottle to make rice porridge for the family. The woman and her parents all got sick, Dolge wrote.

Her mother was the one to suggest that something might be wrong with the water, according to court records.

Victim's spy camera helped police solve the case

Dolge described how the victim later set up a spy camera in her office after she and her parents all fell ill.

According to Dolge, the victim caught Xu on camera twice in her office.

Read more about crime in Berkeley.

The first time, in February 2019, Xu was "apparently manipulating something on her desk" in the area of her water bottle, but the camera angle was limited, Dolge wrote.

In March 2019, "the camera captured [the] defendant entering the victim's office, unscrewing her water bottle, and pouring what appears to be a liquid into her water. Defendant leaves but returns soon to adjust the bottle so it is left in the same position as it was before."

The woman gave the water samples to Berkeley homicide investigators and told police she was afraid of Xu because "he was highly intelligent and would know how to poison someone," according to court records.

Subsequent testing of the water samples found "extraordinarily high levels of cadmium, a poisonous heavy metal," Dolge wrote.

Berkeley police consulted toxicology experts at the University of California San Francisco and tested the woman and her parents for signs of poisoning.

"Test results showed all three victims to have elevated levels of cadmium in their blood," Dolge wrote.

He wrote that, while the exact timeline might be tough to establish, the woman's "blood levels were consistent with being exposed to heavy metal poisoning over weeks or months."

David Xu poisoning case leads to sentence of probation

Xu, who is now 39, was convicted of one count of poisoning in September 2023.

The second count of poisoning and the attempted murder charge were dropped as a result of the plea deal.

Last month, Xu received a sentence of probation through March 2026, according to court records.

In the early days of the case, he served 10 days in jail, according to court records. He has otherwise been out of custody.

Attorneys are still trying to come to an agreement regarding restitution, which has been capped at $10,000, according to Xu's defense attorney, Julia Jayne.

Xu, who declined through his attorney to comment for this story, is set to return to court in May to continue that discussion.

He did tell probation officers last year that he had committed no new offenses while on house arrest, according to his probation report.

"He plans to continue obeying the law," the probation officer wrote. "He has also been employed for the last 2 years and was self-employed prior to that."

The probation officer recommended two years of probation for Xu, according to the report.

"The defendant is highly educated and living at home with his wife and children," the officer wrote. "He is employed and earning a stable income. Although this matter represents the first and only offense, it was serious in nature and could have resulted in death or serious illness of the victims."

He continued: "It is the hopes of this deputy that the defendant will take advantage of this second chance and can satisfactorily complete this probation."

Authorities never publicly shared a possible motive for the crime.

But one investigator who is familiar with the case said professional jealousy likely played a role.

In her letter to the court last year, the victim said she can only work half-time due to her ongoing health issues. She also alleged financial losses of more than $460,000.

"I have concerns that the criminal may use his expertise in chemical engineering and fire investigation to commit future crimes, such as poisoning or arson," she wrote. "I request the court to directly allocate the restitution from the criminal's bail and put the remainder to California's victim fund for other victims."

Cadmium, which is primarily used in batteries and also appears in pigments, coatings and platings, is a metal found in the earth's crust, according to the Agency for Toxic Substances and Disease Registry.

Longtime exposure to lower levels of cadmium can cause kidney damage and weaken bones.

"Eating food or drinking water with very high cadmium levels severely irritates the stomach, leading to vomiting and diarrhea, and sometimes death," according to an agency report from 2012.

Read more exclusive courthouse coverage on The Berkeley Scanner.