A knife and a bare derriere got a man in trouble with the Kaiserslautern police. (Jochen Tack/Mettman Police)

A 54-year-old man who flashed Kaiserslautern police his buttocks Saturday after being asked for identification landed in double trouble.

Officers found a knife on him during a routine stop on Luisenstrasse, according to a police report. The knife he was carrying is restricted in Germany under the Weapons Act, police said.

The man was so angry that he “showed the officers his exposed butt, which in turn led to the next police report,” the Kaiserslautern police said.