Woman arrested for poisoning 12 friends with cyanide

Sararat Rangsiwuthaporn, 32, was arrested by Thai police in Bangkok on Tuesday following inquiries into the death of a friend while the pair were on a trip together earlier this month.

Police say the victim, Siriporn Khanwong, travelled with Sararat to Ratchaburi province, west of Bangkok, on April 14.

While there they took part in a Buddhist protection ritual at a river. Shortly after, Siriporn collapsed and died on the riverbank.

An autopsy found traces of cyanide in her body and concluded heart failure as the cause of death. Police allege her phone, money and bags were missing when she was found, according to media reports.

Authorities said the other alleged victims had died in a similar way in incidents dating back to 2020. They did not name any other victims.

Police allege Sararat – who is four months pregnant – knew all of the victims and killed for financial reasons.

Sararat has denied all charges. Thai authorities have denied her bail.

On Thursday, police announced they were expanding their investigation to look into at least 13 suspicious deaths across five provinces in the country, most to the west of Bangkok.

“She has been charged with premeditated murder,” Thai police assistant national police chief Surachate Hakparn told reporters in Bangkok, CBS reports.

Thai police have also questioned Sararat’s ex-husband – who is a senior police officer in Ratchaburi province, where her friend died – and witnesses.

They have also reportedly collected evidence from her car and home, where they found a substance believed to be cyanide used to poison alleged victims’ food and drink.

Another friend, who police believe was targeted by Sararat, narrowly avoided death by vomiting up allegedly poisoned food she was “lured” to eat. Police say the woman loaned 250,000 baht (more than $A11,000) to Sararat.

Relatives of other victims had also reported missing jewellery and cash after their death but, at the time did not suspect foul play. Police say that may make further investigations a challenge.

“As no case was filed (at the time of such deaths) there wasn’t any investigation of crime scenes, or anything,” chief Surachate said on Wednesday, The Guardian reports.

Thai police Crime Suppression Division chief, Major-General Montri Theskhan said if the evidence shows Sararat has committed other alleged murders, she “will fit the description of a serial killer”, The Independent reports.

A lethal dose of cyanide can be detected in corpses several months after death. But some victims’ bodies have been cremated, further complicating efforts to gather evidence.

The poison acts by starving the body’s cells of oxygen, which can induce heart attacks. Early symptoms include dizziness, shortness of breath, and vomiting.

The use of cyanide is heavily regulated in Thailand, and those found to have unauthorised access to the poison could face up to two years in jail.