Woman Arrested Over Fatal Assault on Brother-in-Law

A 41-year-old woman, Rieko Mochizuki, has been arrested in Shibukawa, Gunma Prefecture, on suspicion of fatally assaulting her brother-in-law, Sumio Mochizuki, at their shared home in February 2025. According to police, Mochizuki allegedly kicked Sumio in the chest, abdomen, and other parts of his body, causing fatal injuries. Sumio, also 44 and unemployed, was taken to a hospital upon arrival and was pronounced dead.

Emergency services were initially called to the scene by Mochizuki, who reported that her husband's brother had fallen from a roof. However, investigators found inconsistencies at the scene, including a body position that appeared unusually distant from the roof and older injuries on Sumio's body inconsistent with recent trauma.

These findings led police to suspect Mochizuki had assaulted Sumio, resulting in his death. Mochizuki has admitted to the allegations, stating she was dissatisfied with Sumio's behavior and lifestyle. Police are investigating potential prior assaults.