Lt. Blaise Dresser said employees notified deputies Monday afternoon, 16 hours after the incident.
According to an incident report, a man entered the store shortly after midnight and said he was on crack cocaine and needed help.
He then pulled a pocket knife and demanded money from the register.
The report said the 19-year-old employee called for help from the cook, causing the man to flee.
Dresser said employees said they didn’t initially report the incident because they didn’t think the robber was serious.