Thailand’s Criminal Court handed serial killer Sararat Rangsiwuthaporn another life sentence on Thursday, convicting her of fatally poisoning a policewoman in Khon Kaen province — the third major ruling in a case that has gripped the country for three years and shows no sign of being over.
Sararat Rangsiwuthaporn, convicted of poisoning at least 14 people across seven Thai provinces between 2015 and 2023, faces more trials as courts work through each victim’s case separately Photo Courtesy ABC News
The court found Sararat, 39, guilty of mixing potassium cyanide into a meal and beverage consumed by Police Captain Sukanda Wimolman on August 9, 2022. Judges initially handed down a death sentence, then reduced it to life imprisonment on the grounds that the defendant provided useful testimony during the trial, according to several news sources.
The ruling adds to an already staggering accumulation of penalties. Sararat now carries one death sentence — handed down in November 2024 for the murder of her friend Siriporn Khanwong — and a prior life sentence from February 2026 for the cyanide killing of Police Major Nipa Saenchan in Nakhon Pathom. Three cases have now concluded. Several more are pending.
The case surfaced in April 2023 after Siriporn collapsed and died beside the Mae Klong River in Ratchaburi, where she and Sararat had gone to release fish as a Buddhist merit-making ritual. Sararat did not try to help her friend when she fell. Instead, according to court findings, she walked back to her car and drove away with Siriporn’s belongings and cash. A subsequent autopsy confirmed cyanide poisoning, and what followed was one of the largest criminal investigations in Thai history — 900 witnesses, more than 26,500 pages of evidence, and a pattern of suspected killings stretching back to 2015.
Police linked Sararat to 15 poisonings across seven provinces. Fourteen victims died. Only one survived. According to investigators, she targeted friends, acquaintances and people she owed money to, allegedly lacing their food, drinks or herbal supplements with potassium cyanide. The suspected motive was financial: prosecutors say she had accumulated heavy online gambling debts and was borrowing from and then killing those around her to avoid repayment.
Her ex-husband, Withoon Rangsiwuthaporn, a former police officer, was convicted and sentenced to one year and four months in prison for helping conceal evidence. Her lawyer at the time received a separate prison term for the same reason.
Sararat has denied wrongdoing throughout. Her legal team has indicated she plans to challenge the convictions.
The case forced a broader national conversation about the regulation of toxic chemicals in Thailand and about how a string of suspicious deaths — most initially ruled as natural causes — went uninvestigated for years. The courts are expected to continue working through the remaining trials, with each victim’s case being tried separately.
