The Supreme Court on Tuesday upheld the death sentence given to a 74-year-old woman dubbed the "black widow" for murdering her husband and two common-law partners with poison in western Japan between 2012 and 2013 to inherit money and escape debt.

Chisako Kakehi | KYODO
Chisako Kakehi | KYODO

The top court rejected an appeal by Chisako Kakehi in line with prosecutors' demands, clearing the way for her death sentence to be finalized soon.

Kakehi's lawyers had earlier this month demanded another psychiatric evaluation for her, claiming her dementia has gotten progressively worse and she does not understand that she has been taking part in a criminal trial.

According to lower court rulings, Kakehi murdered her 75-year-old husband, Isao Kakehi, and common-law partners Masanori Honda, 71, and Minoru Hioki, 75, as well as trying to kill her acquaintance Toshiaki Suehiro, 79, by having them drink cyanide between 2007 and 2013.

The killings in western Japan drew public attention, with the media portraying her as a woman who preyed on wealthy and older men.

Kakehi, who registered with a matchmaking service, married or was associated with more than 10 men and inherited about ¥1 billion ($9 million), but she eventually fell into debt following her attempts to speculate in stock and futures trading.