A Bangkok court found the woman Thai media called "Am Cyanide" guilty of poisoning her friend Siriporn Khanwong with cyanide; police link her to 14 deaths since 2015.
Published

It took three hours, from 9:30 in the morning until 12:30 in the afternoon, for the judges of Bangkok's Criminal Court to read their verdict on November 20, 2024. At the end of it, Sararat Rangsiwuthaporn, 36, the woman Thai media had named "Am Cyanide," was sentenced to death for the premeditated murder of her friend Siriporn Khanwong. It was the first of 14 murder trials she faced.
The court found that on April 14, 2023, Sararat poisoned Siriporn, 32, with potassium cyanide by contaminating something she consumed, then made off with belongings worth 154,630 baht. The two women had met near Bangkok that April to release fish into the Mae Klong river as part of a Buddhist ritual. Siriporn collapsed and died soon afterward, and investigators found traces of cyanide in her body. Her family refused to accept that she had died of natural causes, and their refusal set off the investigation that followed.
Two others were convicted with her. Police Lt. Col. Withoon Rangsiwuthaporn, 40, her ex-husband and a former deputy superintendent of the Suan Phueng police station, received one year and four months in prison for tampering with evidence. Her lawyer, Thannicha Aeksuvanwat, 36, was sentenced to two years without suspension. All three had pleaded not guilty. Sararat remained in custody at the Central Women's Correctional Institution; the other two were granted bail. Through the long reading, she showed no emotion, and she and her co-defendants were seen chatting and even laughing.
Siriporn's mother, Thongpin Kiatchanasiri, wept when the sentence came. "The court's decision is just," she told reporters. "I want to tell my daughter that I miss her deeply, and justice has been done for her today."
Siriporn's death opened a far larger case. In an inquiry led by then-Police General Surachate Hakparn, investigators interviewed more than 900 witnesses and examined some 26,500 documents. Police concluded that Sararat was responsible for 15 poisonings in eight provinces between 2015 and 2023, in which 14 people died and one survived. Police said she borrowed money from her victims to feed an online gambling habit, in one case as much as 300,000 baht, before killing them and taking their jewelry and phones, and that she persuaded them to swallow poisoned "herb capsules." She had been charged with around 80 offenses in all, with 13 more murder trials still ahead. Decha Kittiwithayanan, the lawyer for the plaintiff in Siriporn's case, said the ruling, the first judgment in her cases, could set an important precedent for the trials to come.