DEERFIELD BEACH, Fla. (AP) -- A Florida Wal-Mart employee is facing charges after allegedly shooting a co-worker's car window because she won an employee-of-the-month award. Sonia Diogene told Broward Sheriff's deputies that Willie Mitchell became angry after she received the award last month and started harassing her, saying he had helped her numerous times and that he was the one deserving recognition. As the two argued about their workload, Mitchell grew angry. Diogene told her supervisor that she felt threatened by Mitchell after he repeatedly said "I'm gonna show you,' according to an arrest report. Witnesses told authorities they tried to calm Mitchell down during the argument. A Dec. 1 surveillance video showed Mitchell pulling alongside Diogene's car, shooting out a window and driving away. Diogene was not in the car at the time, but told investigators she found the damage when she went out to her car on her lunch break. "It definitely seems unusual for someone to be upset to the point that they would fire a shot into someone else's vehicle just because this person received an award," said sheriff's spokeswoman Keyla Concepcion. "He felt obviously that it was unjust for her to receive this award." Mitchell is charged with discharging a firearm from a vehicle. Jail records did not show whether he had an attorney. A Wal-Mart spokewoman said Mitchell was fired after the alleged incident. "This is an unfortunate situation and we're grateful no one was hurt," said Wal-Mart spokeswoman Dianna Gee.