Nothing new. American author of “Nanjing Massacre” caused a roil in Japan that she feared right wing Japanese gov factions would hire Japanese organized crime to kill her. Last time her mother heard her was she was being followed and decided to buy a handgun for protection. Within a month she was found one gunshot to the head and her handgun was found near her. Ballistics match the bullet to the gun and the US police ruled suicide. Japanese press reported she suffered depression and killed herself. No suicide note was found.
I met her in Japan, and knew about all the threats —they were pretty serious.
IIRC, she had a 1.5 year old (or even younger) at the time of her death.
Her folks think it was suicide:
In the immediate aftermath of their daughter's death, rumours circulated that she had been murdered. She had received death threats because of her research on the atrocity. "We don't believe she was targeted," her mother says now as her husband, Shau-Jin Chang, watches her, nodding his head solemnly. "We knew she was suicidal. She left a suicide note."
Some of those depression drugs are dangerous. I don't know if it's a matter of people developing a tolerance and having to up their dosage to get the same effect, which leads to problems, or something else.