Ernest Hernandez is charged with aggravated robbery in the incident.
Police say he used a gun to hold up the store clerk.
The clerk testified for the prosecution today, telling jurors she's certain the defendant in the case is the man who committed the crime.
She says he drew a gun and ordered her to the ground and took nearly $14-hundred from the cash register, then took all her identifying information and cash from her purse.
WFPD Detective Rick Cullar, the lead investigator in the case, also testified.
He says officers began investigating Hernandez after they received a Crime Stoppers tip.
Surveillance video shows a person entering the store at about 10:45 that morning and leaving the store less than 40 seconds later.
An arrest affidavit states the clerk also recognized Hernandez's voice.
She says he made repeated calls to the store asking if she had any customers in the building.
Police say they traced those calls back to Hernandez's home.
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