About a dozen men who answered a job ad on Craigslist discovered too late that their employer was a bank robber who had hired them to assist his getaway by dressing as decoys.

According to Seattle CBS affiliate King5, a man wearing a construction respirator mask assaulted an armored car guard with pepper spray in Monroe, Wash., on Tuesday and ran off with the bag of money the guard had been carrying.

The robber fled on foot toward a nearby creek, and one witness said he floated away on a waiting inner tube.

To confuse pursuers, the robber had placed an ad on Craigslist for workers for a road maintenance project. The ad promised $28.50 an hour.

Those who answered the ad were told to meet near the Bank of America in Monroe, at 11 a.m. on Tuesday. They were told to wear a "yellow vest, safety goggles, a respirator mask ... and, if possible, a blue shirt," said Mike (no last name given), according to King5's report.

The robber was dressed the same way.

It's not clear whether the dozen or so identically clad would-be workers made life harder for the police investigating the crime. But the incident demonstrates how effective social engineering cons can be, online or offline.