Police have found evidence linking Apichai Ongwisit, dubbed "Ice Metal Casket", to six cases, including rape, abduction and murder according to the Metropolitan Police Bureau.
Pol Lt Gen Phukphong Phongpetra, chief of the MPB, said three of the cases involve firearms and drug charges while the others involve rape, detention and murder related to the discovery of the body of his girlfriend and hundreds of other human bones.
Apichai was arrested earlier this month after police found the body of Warinthorn "Kuk-kik" Chaiyachet, 22, from Sakon Nakhon, wrapped in a plastic bag and buried on the man's property at the end of Soi Phetkasem 47 in Bang Kae district.
As the investigation proceeded, police came to believe there were more victims and a search of a pond near the suspect's house found more than 300 human bone fragments.
Pol Lt Gen Phukphong said the evidence suggests there have been at least three victims; the first was Warinthorn and two other females -- one is believed to have been between 15-18 and the other an adult.
He said police are looking into a large number of missing persons complaints which may help them identify the two other victims.