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Former chemistry student pleads guilty to poisoning roommate

Yukai Yang likely to face 6–12 years in prison

by Dalmeet Singh Chawla, special to C&EN
November 30, 2020



On March 24, 2021, Judge Stephen Baratta of the Northampton County Court of Common Pleas sentenced Yukai Yang to serve 7–20 years in prison, including the time he has already spent incarcerated. The Pennsylvania prison system will determine when he may be paroled. Yang must also pay $19,000, which will go toward Juwan Royal's out-of-pocket medical expenses and the costs of prosecution.

A former chemistry student has pleaded guilty to poisoning his roommate with highly toxic thallium.

Photo of Yukai Yang.
Credit: Northampton County Department of Corrections/Associated Press
Yukai Yang

Yukai Yang, an international student from China who was completing an undergraduate degree in chemistry at Lehigh University, has been imprisoned without bail since January 2019. Before that, Yang allegedly tried to get himself deported to avoid prosecution, according to the Associated Press.

On Nov. 30, Yang pleaded guilty to attempted murder, causing serious bodily injury, as part of a plea deal with prosecutors. Specifically, he admitted purchasing thallium from the internet to poison his former roommate Juwan Royal in front of Judge Stephen Baratta at the Northampton County Court of Common Pleas.

Yang had also been charged with recklessly endangering another person, aggravated assault, and simple assault, although those charges were dropped as part of the deal. In 2018, he was also charged with ethnic intimidation after writing racist graffiti in the room he shared with Royal.

Yang mixed thallium, a substance that is colorless, tasteless, odorless, and toxic to multiple organs, into Royal’s food and drink in March 2018.

“This poisoning caused serious bodily injury in the nature of diarrhea, vomiting, skin lesions, syncope, dizziness, and, most severely, neurological effects in the nature of bilateral polyneuropathy,” which involves damage to peripheral nerves, Katharine R. Kurnas, assistant district attorney in Pennsylvania’s Northampton County District Attorney’s Office, tells C&EN. “The victim continues to have no feeling whatsoever in his bilateral toes, more than two and a half years after the poisoning.”

Police had reportedly found traces of the toxic metal cadmium in Yang and Royal’s shared room, but Royal’s blood samples only yielded traces of thallium.

“My understanding is that Mr. Yang must serve his minimum sentence of incarceration before he can be deported to China,” Kurnas says. She predicts that Yang will face 6 to 12 years in prison but notes that the judge has discretion to issue a sentence as long as 40 years. The sentencing for Yang’s case is scheduled for Jan. 21, 2021.

“As the judicial process runs its course, our thoughts continue to be with Juwan Royal and his family,” a Lehigh University spokesperson says.

In December 2018, Zijie Wang, a former chemistry doctoral candidate at Queen’s University in Canada and who was also an international student from China, was sentenced to 7 years in prison after confessing to adding the carcinogen N-nitrosodimethylamine (NDMA) to his colleagues’ food and drink.


This story was updated on Dec. 1, 2020, to correct misspelling of the poisoning victim's last name. It's Royal, not Ruwal.



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