Japanese widow Chisako Kakehi was sentenced to hang on Tuesday by Kyoto District Court, after being convicted for murdering her husband and two other lovers, plus the attempted murder of a fourth man.
Another focal point was whether Kakehi bears criminal responsibility, as the defense claimed that she was suffering from dementia at the time of the incidents.
While dismissing the possibility of suicide, accident or the involvement of persons other than Kakehi in the cases, the judge said the accused took extraordinary acts, such as inheritance procedures, soon after the incidents. The name comes from a female spider which is known to kill its mates after sex.
The presiding judge, Ayako Nakagawa, stated that extenuating mental health issues could not explain away the extreme nature of her history, saying, "It was a heinous crime driven by greed for money".
Prosecutors maintained that in all four cases, the victims were tricked into drinking cyanide given by a debt-ridden Kakehi, who was seeking to inherit their assets.
Kakehi's lawyers have filed an appeal, and if Kakehi's sentence is upheld, it could be a long time before her execution. She would then trick them into making her the beneficiary of their insurance payouts and later kill them using cyanide which she had kept hidden in a plant pot at her home.
Defense lawyers, however, argued that Kakehi could not be held responsible, saying her dementia had progressed and that she was unable to comprehend that she was defending herself at trial.
Asked whether she was fully aware of the potential repercussions to the admission, Kakehi said "yes".
Judge Nakagawa noted that cyanide was detected in one of the three murdered victims and the man who survived, and recognized that the other two died of cyanide poisoning based on their condition when they were taken to hospital by ambulance.
Kakehi first Wednesday at the age of 24, launching a fabric-printing company in Osaka Prefecture with her first husband.
Kakehi used to befriend wealthy and mostly elderly and sick men who did not have any children. She made over $8.8 million in insurance payouts over a decade, though supposedly lost most of it in the stock market.
The trial was held under Japan's lay judge system, which involves citizen judges.