ST. LOUIS -- Police say a St. Louis gas station clerk who allegedly shot a man to death last month believed the victim was stealing a bag of candy, reports CBS affiliate KMOV.

The clerk, Taleb Rebhi Ali Jawher, 39, is charged with first-degree murder and armed criminal action. According to police, 34-year-old Christopher Simmons was found outside the store with a gunshot wound to the head.

Court documents say Simmons and Jawher were arguing inside the store on the day of the murder. Jawher then allegedly pointed a gun at Simmons as Simmons left the store.

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Authorities said Jawher believed Simmons was intending to steal a bag of candy, but that Simmons didn't actually steal the candy.

Jawher is accused of following Simmons outside the store and shooting him in the head as Simmons walked to his car.

Simmons' mother told KMOV she is relieved that charges have been brought against Jawher.