SAN ANTONIO -- A man who attempted to rob a San Antonio McDonald's on Tuesday evening ran into a string of bad luck, police said.

The man approached a cashier at the McDonald's in the northwest part of the city and demanded money, only to be laughed at when the cashier didn't realize he was trying to rob the store, police said.

The cashier told the man to get a job if he wanted money, reported KSAT-TV in San Antonio. The man then pulled a box cutter out on a couple inside the restaurant and demanded the patron's wallet.

The patron complied, police said, but there was no money in the wallet.

The would-be robber left the store and was promptly caught by a police officer who responded to the call from across the street. The man is expected to be charged with aggravated robbery, police said.