Hanoi police arrested a local man on Sunday, four days after he shot his wife and three other people in the capital city.
Police recovered a Colt pistol and 29 bullets when they caught up to Nguyen Anh Tuan, 36, in Vinh Yen Town, Vinh Phuc Province.
Tuan told police he bought the firearm in the border province of Lang Son to exact revenge on his wife, who was seeking a divorce.
Tuan said he'd been fighting with his wife and members of her family for a year before he decided to commit his gruesome assault.
At around 11:30 p.m. on December 10, Tuan drove to the home of Hoang Thi Nhi, his mother-in-law, and picked a fight.
Eventually, he drew his weapon and opened fire on the 62-year old woman.
When his wife, Le Thi Hue, 36, heard the shots and ran into the living room, Tuan shot her as well.
Tuan also shot Hue’s younger brother, Le Xuan Nam, when he ran downstairs.
Tuan fired his last shot at a taxi driver who had pulled into the alley after being called by a neighbor.
Tuan assumed the driver had come to take his victims to hospital.
After the perpetrator fled the scene, a second taxi came and drove the injured driver, Ngo Cong Hung, to the hospital with Tuan's three other victims.