Traces of cyanide have been found in the car of the suspect in a series of cyanide poisonings and traces of an antidote were found in a parcel addressed to her, according to Associate Professor Weerachai Phutdhawong, a lecturer at the Chemistry Department of Faculty of Liberal Arts and Science at Kasetsart University.

Crime Suppression Division officers sought help from Weerachai, an expert in chemical substances, by examining some of the evidence obtained in their investigation into the deaths of at least 13 people, thought to have been poisoned by a woman called Sararat, aka “Am”.

Weerachai said that he has checked items of evidence, collected from Sararat’s car, which were sent to him by the police, and found that evidence obtained from the right side of the front console of the car contains residual cyanide.

He also said that the residue of a transparent substance found in a parcel addressed to the suspect was identified as sodium thiosulfate, which is an antidote to cyanide.

Sodium thiosulfate is used by fish and shrimp farmers, he said, adding that Srarat may have some knowledge of chemistry and ordered the chemical to be sent to her.

Police in Don Toom district of Nakhon Pathom questioned the father of a suspected cyanide victim, Paibul Samboonmee, on Thursday, whose daughter, Pusadee, a former school teacher, died on November 20th last year.

He said he does not know when her daughter encountered Sararat, but only knows that they were members of a “share” money lending scheme and her daughter used to describe Sararat as a “good person”.

He claims that Sararat came to see him in Nakhon Pathom on December 5th last year, to ask for a “share” payment owed by her deceased daughter, but he declined, claiming that he had no knowledge of the debt.

Pol Col Anek Taosuparb, deputy commander of the CSD, said police will file another charge against Sararat related to the death of Pol Maj Nipa Saengchan, who died from sudden heart failure at the Phra Pathom Chedi in Nakhon Pathom on April 1st.

CCTV footage shows Sararat at the scene where the police officer collapsed and the autopsy report shows traces of cyanide in the victim’s blood.