Duong Van Nuoi, 30, has been detained pending criminal charges for murder.
Nuoi told investigators he just wanted to “save his deadlocked life.” He wanted to commit suicide but was afraid of dying alone, he said.
And he chose to end his life with his boss at the Huong Sinh advertising company, an office-cum-residence.
Nuoi was hired by the company to put up billboards, as the company's owner, Le Cong Quang, 39, was his brother's friend.
He first repaired vehicles in front of the company in 2005 after serving one year in jail for robbery.
The business failed, so Nuoi went back home to Binh Dinh Province and just returned two months ago to be employed by Huong Sinh, who were then short of staff.
Workers at the company said Nuoi has gotten along well with people, showing no signs of mental problems but had looked listless of late.
His suicide attempt sent seven people in Quang’s family to the hospital, including his wife Phan Thi Kim Chi, 30, his son Le Cong Quoc Thang, 13 months old, and his brother and sisters.
Nuoi had armed himself with two hammers around 0.3 meters long each. He used the hit himself as well.
The victims of the unprovoked attack sustained severe injures as it happened at around 6 a.m. when they were still asleep.
One of the injured, Le Thi Hong Hoa, 24, said Nuoi came from a poor family of six children. He'd once told her that he was deeply in debt, local news website Dan Tri reported Monday.
Police are gathering more evidence in the case before taking a decision on prosecuting Nuoi.
A home helper in Ho Chi Minh City brutally assaulted seven members of his boss' family with a hammer on Sunday before trying to kill himself with it.