A Japanese man has been handed to prosecutors for further questioning after police said he confessed to killing and dismembering nine bodies found in his apartment.
The questioning by prosecutors is a procedure before formal indictment.
So far, Takahiro Shiraishi, 27, only faces a possible charge of abandoning bodies, but police are expected to seek murder and dismembering charges.
Officers arrested him yesterday after finding eight female and one male bodies in cold-storage cases, covered with cat litter and hidden in his apartment in Zama, a city south west of Tokyo.
Police say Shiraishi confessed he tried to hide the evidence.
Officers found the bodies while searching for a 23-year-old woman who had disappeared after exchanging Twitter messages with him. They are working to identify the victims, saying she might be among them.
The gruesome case captured attention in a country known for public safety, topping news with reports that showed the building where the suspect lived in a small studio apartment.
On Wednesday, media reports quoted investigative sources as saying Shiraishi started killing as soon as he moved into his apartment in late August.
His first victim was a woman who made contact on Twitter, and he offered to assist her suicide wish, and then killed her boyfriend to silence him, according to media reports, including NHK public television.
Shiraishi reportedly used similar tactics to kill seven other women.
A police official said tools found in Shiraishi's apartment may have been used to dismember the bodies.
Online descriptions of the apartment building indicate it had a plastic-sealed "unit bath" and he allegedly dismembered the bodies there.
Reports said the missing woman got in contact with Shiraishi on Twitter, seeking a partner for a suicide pact and saying she was afraid to die alone.
The two were recorded by security cameras walking together outside train stations near her apartment and the suspect's apartment, the reports said.
He told police his motives were money and sexual abuse, Japanese media reported.