Investigators will present their case reports against accused serial killer Sararat "Aem Cyanide" Rangsiwuthaporn to prosecutors on Friday, deputy national police chief Pol Gen Surachate Hakparn said on Monday.
Pol Gen Surachate was speaking at the Correctional Institution for Women in Bang Khen area of Bangkok, where Ms Sararat is beng detained.
The deputy police chief filed additional charges against Ms Sararat during his visit. She was earlier charged with premeditated murder and forgery in the case of Siriporn "Koy" Khanwong, one of her 15 alleged poisoning victims.
Pol Gen Surachate said Ms Sararat faced similar charges in all cases - including premeditated murder, poisoning, forgery and theft.
He said the police reports on the 15 cases were complete. He had consulted prosecutors before wrapping them up.
All charges against Ms Sararat were supported with strong evidence, he said. If found guilty she could face the death penalty, but the court could reduce this to life if she confessed. For now, she was still regarded as innocent.
The deputy national police chief said investigation reports on the cases against her former husband, Pol Lt Col Withoon Rangsiwuthaporn, and her lawyer, Thanicha Aeksuwannawat, would also be forwarded to the prosecutors on Friday.
Pol Lt Col Withoon, former deputy superintendent of Suan Phueng police station in Ratchaburi province, was charged with receiving stolen property and forging and using official documents. Ms Thannicha was charged with assisting her client destroy or conceal evidence of a crime.
Pol Gen Surachate was full of praise for all police investigators handling the cases, saying they had worked hard and carefully.
The 15 cases spread over seven provinces - Nakhon Pathom, Samut Sakhon, Kanchanaburi, Phetchaburi, Ratchaburi, Udon Thani and Mukdahan.
Ms Sararat was arrested on April 25 following a complaint filed by the mother and elder sister of Siriporn "Koy" Khanwong, 32, of Kanchanaburi, one of her 15 alleged victims.
Most victims were linked to the suspect through private savings schemes and car financing deals. All the deceased were found to have been with Ms Sararat shortly before they died.