Thai authorities have arrested 35-year-old Sararat “Am” Rangsiwuthaporn, a woman suspected of being a serial killer responsible for the deaths of 12 people.

The arrest came after her friend, 32-year-old Siriporn Khanwong, collapsed and died during a trip to Ratchaburi province in western Thailand on April 14.

An autopsy found cyanide in Siriporn’s system, with heart failure cited as the cause of death. Sararat, whose ex-husband is a senior police officer and whose sister owns a pharmacy where suspicious capsules were found, was discovered to have a bottle of cyanide on her person at the time of her arrest.

Local news outlets report that police have identified 12 individuals who died from heart-related conditions between 2020 and 2023, all of whom had contact with Sararat. The deputy national police chief, Surachate Hakparn, stated that there may be two more victims linked to the accused, including two policewomen.

Sararat’s attorney maintains her innocence, while authorities investigate possible financial motives behind the alleged killings. Family members of the victims have reported missing personal belongings and money from bank accounts.

Following Siriporn’s death, her mother reported missing money and jewelry. Another woman who lent money to Sararat claimed to have experienced chest tightness and numbness in her hands after taking a pill given by the accused. The woman was hospitalized and has since recovered.

Surveillance footage of Siriporn’s collapse led to the issuance of an arrest warrant for Sararat, who was taken into custody on April 25. The court has denied her bail, and she remains in a women’s correctional institution as investigations into the suspected murders continue.