An A*Star scholar was arrested and charged in California, US, with allegedly poisoning herself and her classmates.
Ouyang Xiangyu, 26, a second-year student at Stanford's School of Medicine, had put paraformaldehyde (PFA) in her drinking water and in her classmates' water bottles.
PFA, commonly used in biology, is lethal if ingested in sizeable amounts.
Ouyang was described as an awkward and quiet girl with no friends and had once asked a classmate what it was like to have a boyfriend.
The Singaporean has pleaded not guilty by reason of insanity.
She is no longer a student at Stanford after the university issued a Stay Away Letter to her on Nov 11. This was after her classmates had found PFA in their water bottles on multiple instances from September to November last year.
Two of the students had drunk the poisoned water and complained of a burning sensation in their mouths and throats.
Ouyang claimed that she had added PFA and other unknown chemicals to her own water bottle without having an adverse reaction.
She had also allegedly destroyed some of the projects that the other cancer biology students were working on.
When confronted by classmates, she claimed to be "not conscious" of the act at the time.
Court papers quoted Ouyang as saying: "I am truly sorry for what had happened but I really didn't mean to harm people. It was me crying out for help, and I didn't know."
It was also revealed that Ouyang had been suffering from severe insomnia, dizziness, depression and a "disconnection from reality".
According to Stanford University spokesman Lisa Lapin, investigations began in mid-November.
"This was a sad, heartbreaking situation and no one could speculate as to why," she said.
"The university has been providing support to the group impacted. They are a strong team and from the outset requested privacy to move on."
Ouyang completed her A levels in Temasek Junior College in 2009 and went on to graduate with a degree in biochemistry from Imperial College in London. She completed her degree under the A*Star National Science Scholarship.
Property records show that the Clementi address listed in the court papers belong to the Ouyangs.
When The New Paper visited the address, a woman in her 20s came to the door. The woman, who declined to be named, identified herself as a tenant and said that Mr Ouyang had gone out.
Mrs Ouyang had flown to the US about two weeks ago to be with her daughter, she said.
Ouyang is an only child. The tenant said that in more than a year of living there, she had never met Ouyang, but had spoken to her online a few times.
"Usually it was the mother who went over to the US, even during summer holidays. But she was always fretting about her daughter, flying over once every few months," the woman said, adding that the Ouyangs are researchers.
"Sometimes Mrs Ouyang would suddenly take off, and even her husband wouldn't know where she went until she called him from the US.
"They are really nice people, but I've heard the mother say many times that her daughter was very stressed.
"She told her daughter to take up more exercise and make more friends, but I suppose it didn't help."
An A*Star spokesman said it was aware of the incident and was deeply concerned.
No action will be taken until the proceedings have been concluded.
Ouyang has been charged with four counts of "poisoning any food, drink or medicine".
Under the California Penal Code, the charge carries a jail term of two to five years, with an additional term of three years if the substance may cause death when ingested.
According to Vice News, Ouyang, who is out on US$50,000 (S$68,000) bail, is awaiting further psychiatric evaluation and is expected to be back in court again next month.
Just a few drops can be lethal
Paraformaldehyde (PFA) can cause skin irritation - and also be lethal when ingested.
Assistant Professor Guillaume Thibault from Nanyang Technological University's School of Biological Sciences and the Lee Kong Chian School of Medicine, said PFA is a commonly used substance in biology.
"You need gloves and a lab coat to handle it properly and it should not be ingested," he said.
"Ingesting just a few drops can be lethal."
He said PFA is used to take samples from cell tissue and can react with internal organs.
"It is poisonous and is also a carcinogen. It is definitely not meant for consumption," he said.
He also said that the tampering or damaging of projects can result in the loss of months of work.
"In some cases, the entire research project is lost," he said.
This article was first published on April 2, 2015.
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