Brandon Hall and Darcell Harris are now facing murder and attempted murder charges after investigators say the pair threw some kind of explosive into the shop earlier this month, setting a fire.
They then began shooting at employees, who returned fire.
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Thirty-two-year-old Jason Cullen, who was working inside the store, was killed.
Harris pleaded not guilty to all charges at a Tuesday arraignment. His next court date was set for Jan. 31.