Police who knocked on an apartment door in Japan and inquired about a missing woman were told by the occupant "she is in here" as he pointed to a cooler box, sources said.
More chilling details emerged on Wednesday about Takahiro Shiraishi, 27, who police say confessed to killing and dismembering nine bodies found in his apartment.
Shiraishi was handed over to prosecutors for further questioning.
Police arrested him on Tuesday after finding the bodies, eight females and one male, in cold-storage cases inside his apartment in Zama, a city southwest of the capital Tokyo.
Police have said Shiraishi confessed he tried to hide evidence.
Police found the bodies, some covered with cat litter, while searching for the 23-year-old woman who had disappeared after exchanging Twitter messages, allegedly with Shiraishi.
They are working to identify the victims.
The gruesome case captured widespread 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.
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 another woman whom he got in touch with via Twitter, offering to assist her suicide wish, then killing her boyfriend to silence him, according to the media reports, including NHK public television.
They said Shiraishi used similar tactics to kill seven other women, four of them teenagers.
A police official said a toolbox and saw found in Shiraishi's apartment may have been used to dismember the bodies.
Japanese media quoted his neighbours as saying they had noticed foul smells coming from the apartment.
Shiraishi threw out some of the body parts as rubbish, along with the victims' belongings, reports said.
They said the missing woman contacted Shiraishi via Twitter in late September, 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 railway stations near her residence and the suspect's apartment on October 23, the reports said.
The woman's brother reported her disappearance to police the next day.
When he sought information about his sister's disappearance on Twitter, an unidentified woman replied that she had met Shiraishi and agreed to cooperate with police by setting up a fake appointment.
Two investigators then followed Shiraishi back to his apartment and knocked on the door, public broadcaster NHK said.
When they asked him if he knew where the missing woman was, Shiraishi pointed to one of eight coolers, saying "She is in here", NHK said, quoting investigative sources.