Police Arrest Woman Suspected of Murdering 12 Acquaintances With Cyanide

Investigators think the serial killings were motivated by money.
Gavin Butler
Melbourne, AU
Sararat Rangsiwuthaporn
Sararat “Am” Rangsiwuthaporn was charged with first-degree murder on Tuesday after her friend collapsed during a trip they took together, and later died. Photo: YouTube/Policetv UCI MEDIA

Thai police have arrested a woman on suspicion that she murdered her friend with cyanide, as they investigate the unusual deaths of up to 12 people known to the accused. 

The 35-year-old, identified in Thai media as Sararat “Am” Rangsiwuthaporn, was charged with first-degree murder on Tuesday after her friend, 32-year-old Siriporn Khanwong, collapsed during a trip with Sararat to the western Thai province of Ratchaburi on April 14. Siriporn died shortly thereafter, with autopsy results detecting cyanide in her system and showing heart failure as the cause of death.


Police found a bottle of cyanide in Sararat’s possession during her arrest, according to a report by The Nation newspaper in Thailand. The alleged killer’s ex-husband is a senior police officer, and her older sister owns a pharmacy in Ratchaburi where police found suspicious capsules, according to Coconuts.

Citing an anonymous source, The Nation said that police have compiled a list of 12 people, aged between 33 and 44, who died of heart-related conditions between December 2020 and April 2023 after making contact with Sararat.

Thai deputy national police chief Surachate Hakparn said on Wednesday that there are two more possible victims in connection with Sararat, bringing the total number of suspected killings to 12. At least two of the victims were policewomen.

Sararat’s lawyer said her client has denied all charges.

Authorities are investigating whether Sararat’s alleged victims were targeted for financial reasons. Most of their families have reported either personal possessions missing from their bodies or money missing from their bank accounts.

Shortly after Siriporn’s death, her mother filed a police report saying her daughter’s money and jewellery had gone missing. Another woman who had reportedly loaned Sararat 250,000 baht ($7,330) told police that she had felt tightness in her chest and lost feeling in her hands after taking a pill offered to her by the alleged killer at a mall in the western province of Kanchanaburi. She was immediately sent to hospital and is now safe.

“If the evidence shows she has committed other murders, then the suspect will fit the description of a serial killer,” said police major-general Montri Theskhan, chief of Thailand’s Crime Suppression Division. 


Several murderers in Thailand fit the criteria of serial killers in recent years, including Somkid Pumpuang, otherwise known as Kid the Ripper, who killed five masseuses and nightclub singers between January and June 2005. Nirut Sonkhamhan, otherwise known as the Pickup Truck Killer, poisoned nine taxi drivers with pesticide between 2011 and 2012, at least four of whom died as a result.

One of the most notorious serial killers in the kingdom, a 78-year-old Frenchman named Charles Sobhraj, was released from a Nepali prison in December. Sobhraj, who is known as the Bikini Killer and inspired the Netflix drama series The Serpent, has been linked to over 20 murders between 1972 and 1982 in Thailand, in which the victims were drugged, strangled, beaten, and burned. He was in prison in Nepal on charges of murdering two backpackers in the country. 

Police detained Sararat on Tuesday after CCTV footage showed her most recent alleged victim, Siriporn, collapsing during their trip together, and a warrant was subsequently issued for her arrest. She has been denied bail by the court, who deemed her a flight risk, and is currently detained at the Central Women’s Correctional Institution. 

Police say investigations are still continuing.

Follow Gavin Butler on Twitter.