DURHAM — Durham police are trying to catch an armed robber who seems to specialize in restaurants, and in locking his victims in the freezer.

Detectives say the suspect shows up at restaurants right before closing.

He threatens employees with a gun, locks them in the freezer and makes off with cash.

Employees at a Fuddruckers restaurant in Durham won't forget the night the masked robber walked in with a gun.

Captain Dwight Pettiford says the suspect is armed, dangerous and hard to catch. He hopes somebody has seen something in this area and can help Durham police.

Police say until the suspect is caught all restaurant employees should be careful. And if the public notices activity out of the ordinary around a restaurant, they are asked to call police.

Isaac Nazarro, a Fuddruckers' employee, was one of the robber's victims. Nazarro says it is impossible to think while a gun is pointed at you.

He advises other managers to make sure no "customers" are in their restaurants after closing, check that all doors are locked -- and even check bathrooms to ensure that no one is hiding for an after-hours robbery.

Police know the robber has hit four times on the south side of Durham but they say there have been some similar armed robberies in Raleigh that could be related.

Anyone with information about these robberies is asked to call the Durham Police Department.