A 70-year-old woman dubbed the "black widow" for allegedly murdering her husband and common-law partners with cyanide, pleaded innocent Monday at the first hearing of her trial at the Kyoto District Court.

"I entirely entrust the matter to my lawyers," Chisako Kakehi told the court. The defense team denied the charges of murder and attempted murder-robbery involving four elderly men and said the plaintiff has dementia and cannot defend herself.

Prosecutors aim to use circumstantial evidence to prove Kakehi’s guilt amid a dearth of physical evidence, and more than 50 people are expected to be summoned as witnesses during the trial, which is likely to last until Nov. 7.