The 46-year-old is accused of a serious act of violence after he allegedly lost his temper during an argument at a birthday party on Saturday evening.
First the officer pushed a female guest to the floor with such force that she knocked her head against the ground and lost consciousness. The 50-year-old woman was later taken to hospital for treatment.
The officer then grabbed for a butter knife and tried to stab another guest in the stomach. Luckily for the victim, the policeman failed to properly penetrate his skin, leaving only superficial wounds.
The officer only stopped his rampage when one of the guests hit him over the head with a glass bottle, leaving him with lacerations above his hairline.
When officers arrived at the scene their wounded colleague still refused to come quietly, "massively" insulting and threatening them as they tried to take him in, police report.
After a night in detention, the officer was released.
Police from Mönchengladbach are looking into the incident to ensure the investigation's impartiality.