The number of reported victims of the suspected serial murderer Sararat "Am" Rangsiwuthaporn reached 14 as of Friday, according to police.
Deputy national police chief Pol Gen Surachate Hakparn, leading the investigation, updated the media on findings as investigation teams covering Ratchaburi, Kanchanaburi, Nakhon Pathom, and Phetchaburi provided updates on the case.
Police provided details on cases that have surfaced, including that of Sawittree "Nim" Budsrirak, 41, who passed away in 2020 in Mukdahan.
According to her husband, Pol Snr Sgt Maj Nithipon Nuchid, Sawittree knew the suspect through money lending and a pyramid scheme business and had a debt with her for at least 100,000 baht.
His wife died after taking a "diet pill" that Ms Sararat allegedly sent to her; the autopsy results showed that Sawittree had a high amount of potassium in her bloodstream, said Pol Snr Sgt Maj Nithipon.
Meanwhile, forensics found traces of cyanide in two of four cars seized from the 36-year-old suspect.
Weerachai Phutdhawong, an associate professor in chemistry at Kasetsart University, found traces of cyanide on the right console of the black Honda Civic she used with her ex-husband. The other was found in a bronze Toyota Vios that she drove on the day that Siriporn "Koy" Khanwong, 32, one of her alleged victims, died.
Mr Weerachai also believed that Ms Sararat might have some knowledge of chemistry, citing that she ordered sodium thiosulfate, which is normally used as a cyanide antidote, for herself.
The suspect's sister, who claims to be a pharmacist, has said she is innocent after being accused of providing or using cyanide.
It is understood that the detained suspect, Ms Sararat is pregnant. Soraya Rit-Aram, director of the Central Women Correctional Institution, said the suspect's mental state had improved while her unborn child was in a normal state.
Ms Sararat was apprehended on Tuesday at the government office complex on Chaeng Watthana Road with a bottle of cyanide in her possession.
Her arrest followed a complaint filed by the mother and elder sister of the late Siriporn Khanwong, who died on the bank of the Mae Klong River in Ban Pong district of Ratchaburi. She went with Ms Sararat to release fish for merit-making on April 14. Cyanide was found in her bloodstream.