Stefan H., a 41-year-old laboratory technician, told the Bild newspaper that, while he was out for a walk with a friend, he found the female cat in a plastic bag underneath a rubbish bin in the street.
“We immediately warmed the cat,” he said. “She was whimpering but did not have any outward injuries.”
Two policemen intended to take the cat to the police, but then one decided to shoot it.
They said later they wanted to spare the animal any more pain.
Police spokesman Detlev Rüther said, "we are checking if the legal preconditions for the action were in place. The officers could face disciplinary action."