Prosecutors on Tuesday sought the death penalty for a 70-year-old woman, dubbed the "black widow," charged with the murders of her husband and two common-law partners and the attempted murder of an acquaintance between 2007 and 2013.

Describing Chisako Kakehi's alleged crimes as "heinous and serious incidents that are rarely seen," the prosecutors said in their closing arguments at the Kyoto District Court that the victims — all elderly men — were given drinks laced with cyanide by Kakehi. She was heavily indebted and had been planning to inherit their assets.

The court is scheduled to hand down a ruling on Nov. 7, with the defense making its closing statements on Wednesday.