The three teenagers in hooded black outfits were scampering over rooftops, climbing trees "just like a squirrel," and breaking into houses and cars, police said.
But they weren't quite as slick as their Japanese ninja heroes.
Earlier this summer, an officer chased one of the wannabes across a school rooftop, but the youth leaped into a nearby tree, said police Chief Ken Lewis.
Breaking branches on the way down, "he gave a yelp of pain," and then he scrambled away, Lewis said.
Last week, after months of investigation, police arrested three teens, two 15 and one 16, and seized stolen jewelry, burglary tools, a map of the city and several black ninja suits with hoods and climbing spikes.
The parents of one told police their son complained of an injury about the time of the rooftop chase, Lewis said.
"I believe that's our roof-gliding ninja," said Lewis.