The hold up occurred August 6, 2012, around 6 a.m., at the 7-Eleven at 6001 North Western Avenue near Western and Peterson, on the city's Far North Side.
A Hispanic male, wearing a black T-shirt, entered the business and announced there was a gun inside a bag he was carrying, said police.
Then the thief forced the clerk into a cooler at the back of the store, said authorities.
Apparently, the employee was so traumatized by the experience, police were unable to get more details.
After the robbery, an eyewitness saw the thief running eastbound on Peterson, then northbound on Claremont.
Citing police communications, when this robbery occurred, authorities had to wait three hours before they could access the 7-Eleven's surveillance footage.
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