Japan is transfixed by what's known as the case of the black widow serial killings.
Police believe they have solved the case of a serial killer who befriended lonely men on the internet, defrauded them of thousands of dollars and then murdered them to make it look like suicide.
The ABC reports investigators Kanae Kijima, 34, is suspected of being involved in as many as six killings.
Yoshiyuki Oide, 41, was found dead in his car from carbon monoxide poisoning. In the back seat was a charcoal burner he had used to take his own life, or so it seemed.
It looked like an open and shut case of suicide. But when investigators dug deeper into Oide's case a lot of things did not make sense.
For a start, he had not left a note and had recently been writing on his blog about his plans to pop the question to his sweetheart and take her on the trip of a lifetime.
Police then discovered that there were traces of sleeping pills in his blood, and that he had deposited more than $US60,000 in his girlfriend's bank account days before his death.
The ABC reports another of Kijima's male friends, Kenzo Ando, 80, was also drugged with sleeping pills before dying in a fire.
The day of Ando's death, Kijima was filmed withdrawing money from his account using his ATM card.
