The man's 52-year-old wife called the police at 5:30 on Sunday morning asking for help with her husband. Yet the officers who attended decided there was “no acute threat” and left the house in the Huchting district of the northern German city.
Two hours later the police received a second call - this time from the man's sister-in-law saying the two men were fighting. Both women had been at the house but had fled as the argument between their husbands escalated.
It was later revealed that the man was registered as a gun owner and was known to the police for physically harming his wife, and was under suspicion of illegally hoarding ammunition.
By the time the police arrived, the two men were in the cellar, and officers tried to make contact with them, fearing a hostage situation.
They send in special commandos though, after a gas detector went off, sparking fears the 63-year-old may have deliberately interfered with the gas supply.
His 70-year-old brother was already dead, seemingly of head and chest injuries, although the authorities had not on Sunday evening said how these were inflicted.
Psychologists have been called in to offer counselling to the men's wives.