"He showed up at a bus stop at about 11pm, with the chainsaw running," Peter Jung, spokesman for Saarbrücken police told The Local.
One man was so freaked out he brandished a starting pistol to protect himself, Jung confirmed.
Others called the police for help, prompting the 22-year-old chainsaw-wielder to flee.
Although he denied having anything to do with it when officers called at his house, witnesses had identified him - and his chainsaw was found hidden in the yard.
"There was no chain on the saw - so there was no way he could have actually injured anyone. But equally only an expert could have known that, as he had the thing running," said Jung.
He said it was not yet certain what charges the man would face. "But he will certainly hear from us. And we have kept the chainsaw as evidence - it's quite an expensive one."
The man who drew his starting pistol at the bus stop should also expect to hear from the authorities, Jung said. "He did not have a licence to carry the gun," he said.
"Halloween is a little different to normal nights," added Jung with a sigh.