TOKYO, Dec. 10 (UPI) -- Japanese prosecutors on Wednesday charged Chisako Kakehi, dubbed a "black widow" by the media, with the murder of her 75-year-old husband amid speculation that previous partners may have met a similar fate.
Kakehi was charged with using cyanide to fatally poison Isao Kakehi on Dec. 28, 2013, at their home in Muko, Kyoto Prefecture.
The charges follow her Nov. 19 arrest on suspicion of murder. Traces of cyanide were reportedly found on a sachet in a flower pot she had tried to recycle.
Her previous three husbands and two men she dated all died within several years of meeting her.
According to Japanese media, Kakehi received $6.8 million in insurance money over the past 20 years from the policies of at least five previous partners.
Although Kakehi has declared her innocence, sources close to the investigation told the Japan Times she has in recent days been "wavering."
Police are investigating the death of at least one of the men with whom she had a close relationship. The 71-year-old died of apparent heart failure in March 2012 but upon re-examination of a blood sample taken at the time of his death, police detected a trace amount of cyanide.
It is unclear to what extent investigators will be able to re-examine the cause of death of previous partners because autopsies in Japan are rare.
Two other "black widows" in Japan, Kanae Kijima and Miyuki Ueta, are serving death sentences for killing multiple men.
