Three other arrest warrants have already been issued against Sararat “Am” Rangsiwuthaporn, 36. One for premeditated murder, one for orchestrating a murder, and one for theft.
Colonel Anek Taosuparp, deputy commander of the Crime Suppression Division, said Sarat also faces 11 lawsuits from the families of her alleged victims.
Anek, who is overseeing the high-profile case, said his investigators have already gathered evidence linking the suspect to 13 murders and one attempted murder.
She is alleged to have used cyanide to poison people she owed money to, and to have poisoned a former common-law husband on her birthday.
She was observed celebrating her birthday the day he died, police said.
Anek said the number of people she allegedly murdered has risen to 13.
A police source said on Saturday that the number could continue to rise.
As many as 20 people passed away shortly after transferring money to the suspect during the past three years, the source said, explaining that the number came from an investigation of her bank accounts. That investigation, however, had as of Saturday only gone back three years.
Police previously obtained arrest warrants against Sararat for the deaths of Siriporn Khanwong, 33, a female police officer and a vegetable vendor identified as “Noi”.
Anek was discrete about the details of the arrest warrants being sought, saying: “We must gather as much evidence as possible to make the case strong because this case has shocked the public and is being closely watched.”
Anek said one arrest warrant police are seeking involves an alleged victim whose mother lives in Kamphaeng Phet and another is for an alleged victim poisoned in Bangkok.
Local media have reported that the first accuses the suspect of murdering Monthatip Khao-in, 37, who died on July 7 2015. Her mother, Ladda Khao-in, 64, filed a complaint with police, saying she suspected Sararat was behind the death.
The mother told police her daughter died a day after meeting Sararat and that the suspect had borrowed a lot of money from her daughter. After her daughter’s death, Sararat sold her daughter’s assets but did not give the money from the sales to the deceased’s mother, the complaint alleges.
The suspect was arrested for premeditated murder last Tuesday and is being held in pretrial detention.
The April 14 death of Siriporn sparked a cascade of allegations that Sararat had poisoned other people she owed money to. Families of other suspected victims initially did not suspect they had been murdered and their bodies were cremated before autopsies were performed.
Initially, Siriporn was diagnosed as dying of heart failure, but a friend insisted that a thorough autopsy be performed, including toxicology tests.Cyanide was found in Siriporn’s blood.
Siriporn’s friend then began compiling a list of possible victims and coordinated with their families to file complaints with police.
Many of the suspected victims put money into the suspect’s chit funds.
Anek said on Sunday that investigators believe that Sararat acted alone.
“So far, we have not found information that points to other suspects,” he said.
He said Sararat’s ex-husband, a former deputy chief of Bang Pong police station in Ratchaburi, had been questioned. He has denied any knowledge of the alleged crimes and police have found no evidence linking him to the suspicious deaths.
“If we find more evidence, we’ll summon him for questioning again,” Anek said.
The suspect preyed on the trust of her alleged victims, taking them to temples to make merit before inviting them for dinner or coffee to poison them, police sources said.
“Although there are many victims, it doesn’t automatically mean that there must be many suspects,” Anek said.
The investigation into Siriporn’s death is 80% complete, Anek said. There is no deadline for completing the investigation, he said.
Sararat faces the death penalty for premeditated murder, but because she is pregnant she may be spared capital punishment, a judicial source said.
She was previously hospitalised for amnesia and an anxiety disorder. This may open the possibility of defense lawyers arguing she is unfit to stand trial, a second judicial source said, requesting anonymity due to the outrage sparked by the case.