When the bar manager took the cash drawer into the office, Schaff followed, Gigeous said.
"She thought it was a joke until he put a gun to her neck,'' Gigeous said.
Schaff took about $800 and fled.
A patron followed him out the door and saw him get into a blue pickup truck, Gigeous said. That information plus fingerprints on a glass were given to Hagerstown City Police.
An anonymous caller told police a few days later that Schaff called her from Texas and admitted to the robbery, Gigeous said.
Armed with that information, Jeff Kercheval, police chemist, was able to match the fingerprints on the glass with Schaff's known prints on file, Gigeous said.
Police learned that Schaff had been arrested in Tennessee on a charge of driving while intoxicated and police there saw a BB gun in his vehicle, Gigeous said.
In early June, police went to Cisco, Texas, and brought Schaff back to stand trial.
Other charges, including felony theft, handgun use during commission of a felony, reckless endangerment, assault and battery were dropped in exchange for Schaff's plea Tuesday.