Murder, money, betrayal: Unravelling ‘Am Cyanide’s’ web of deaths
The Nation looks at how Sararat Rangsiwuthaporn made calculated moves to disguise her murders as natural deaths, culminating in her death sentence
On April 19, 2023, Thongpin Kiatchanasiri, 63, filed a complaint at the Central Investigation Bureau (CIB) after suspecting foul play in the death of her daughter Siriporn Chanwong, 32.
Siriporn, the leader of a rotating savings group in Kanchanaburi province, collapsed and died while participating in a merit-making event in Ratchaburi’s Ban Pong district on April 14, 2023. Her belongings, including over 40,000 baht in cash, were reported missing.
The complaint against Sararat Rangsiwuthaporn, 36, then-wife of former deputy chief of the Ban Pong Police Station, Pol Lt-Colonel Withoon Rangsiwuthaporn, raised concerns of possible interference in the investigation and tampering of evidence.
Arrest and discovery of cyanide
On April 25, 2023, Crime Suppression Division officers arrested Sararat and seized cyanide from her house.
Forensic tests on Siriporn’s body showed that she had been poisoned with cyanide and investigators said they suspect Sararat poisoned her so she could steal her belongings. Siriporn was reportedly her 15th victim.
Further investigation revealed 14 additional victims linked to Sararat – 13 of whom had died, but one survived. The victims were linked to Sararat through loans, used car sales and rotating savings groups.
Sararat allegedly meticulously planned these murders, committed over a span of eight years, poisoning her victims with potassium cyanide and making their deaths appear to be from heart failure or other health complications.
The deaths linked to her are:
Monthathip Khaointh: Died from heart failure in Bangkok on July 7, 2015
Nittaya Kaewbuppha: Died from heart failure at her home in Nakhon Pathom on August 22, 2020
Sawitree Butsriruk: Died from unspecified causes in Mukdahan on November 25, 2020
Darinee Thepwi: Died from heart arrhythmia at her home in Nakhon Pathom on December 13, 2020
Surat Trorapap: Died from coronary artery disease at his home in Kanchanaburi on January 6, 2021
Pol Lt-Colonel Kanda Torai: Died from cardiopulmonary failure near Nakhon Pathom’s Global Mall on August 10, 2022
Rojarin Nilhoi: Died from acidosis at Samut Sakhon’s Mahachai Market on August 10, 2022
Chantarat Wongkraisin: Died from unspecified causes in Phetchaburi on August 15, 2022
Maneerat Phojjanat: Died from unspecified causes at Nakhon Pathom’s Phra Pathom Chedi Market on September 10, 2022
Kanika Tuladecharak: Died of a brain haemorrhage at a petrol station in Ratchaburi on September 12, 2022
Kantima Paesaad: Survived an unspecified medical condition at a Kanchanaburi shopping mall in September 2022
Phusadee Samboonmee: Died of unspecified causes in Nakhon Pathom on November 20, 2022. Cyanide was found in a bottle of water in the refrigerator at her home
Suthisak Phunkwan: Died from arrhythmia at his home in Udon Thani on March 12, 2023. Sararat is believed to have been having an extramarital affair with Suthisak
Pol Lt-Colonel Nipa Saenchan: Died from cardiopulmonary failure at her home in Nakhon Pathom on April 1, 2023
Siriporn Chanwong: Died from heart failure near a pier in Ratchaburi on April 14, 2023
Investigators learned that the suspect chose to commit the murders during weekends and would later return to the family or close associates to provide fabricated evidence to divert suspicion.
Monumental investigation
The investigation led by Pol General Surachate “Big Joke” Hakparn, then deputy police chief, became one of the largest in Thai history.
The case file comprised 26,500 pages, involved 900 witnesses and three months of evidence gathering.
Sararat faces 75 charges, including attempted murder, premeditated murder, robbery resulting in death, adulterating food or drink resulting in death and forging documents.
Investigation revealed that the suspect was addicted to gambling and was overburdened with loans from both formal and informal sources. To pay off these debts, the suspect resorted to killings and her three main methods were:
Taking the victim out to a meal before poisoning them with cyanide, then bringing them home where they eventually died.
Picking up the victim from their home, poisoning them and leaving them behind to die.
Sending cyanide-spiked “diet pills” to victims’ homes, ultimately leading to their death.
Court proceedings and verdict
On July 19, 2023, charges were filed against Sararat for poisoning and robbing Siriporn. The suspect’s ex-husband Withoon, and her lawyer Thannicha Akesuwanwat were also charged with concealing evidence and helping her evade punishment. All three pleaded not guilty.
The Criminal Court set the trial dates from July 4 to September 12, 2024, and issued a verdict on Wednesday (November 20).
In its verdict, the court sentenced Sararat, aka “Am Cyanide”, to death for poisoning and killing Siriporn. Withoon received a reduced prison sentence of one year and four months after he cooperated, while the lawyer was sentenced to two years in prison for aiding Sararat.
The case continues to unfold, with authorities investigating 14 more cases linked to the so-called “Cyanide Killer”.
