A man took tomatoes and sweets from the display in Hagen and ate them on site because he said he couldn't pay for them.
The 43-year-old is being investigated for shoplifting.
As the police announced on Thursday, an employee had observed and spoken to the man the day before.
When he reacted aggressively, the police came.
Hagen - The man told the officials that he had no cash with him and could not pay for the groceries.
dpa