An Annandale man pleaded guilty to first degree murder and other charges this week for killing a former co-worker and injuring another when he opened fire in a Fairfax County barbershop in April 2011, a prosecutor said.

Hung T. Nguyen, 46, had repeatedly argued with the two men, but the final straw came when one threw away food Nguyen had stashed in a refrigerator at work, said Fairfax Deputy Commonwealth’s Attorney Katherine E. Stott.

“He was hurt and it humiliated him,” Stott said. “He made a decision he would take revenge and kill them both.”

Nguyen quit working at the Belle View Barber Shop in December 2010, soon after the incident. Nguyen later purchased a gun and wrote letters explaining his plans to family and friends about his plans, Stott said.

On April 13, Stott said Nguyen went to the barbershop under the pretense of signing tax documents. He signed the documents and later opened fire, shooting Le D. Hoang, 39, in the back and wounding another unidentified co-worker in the shin.

Deputy Public Defender Dawn Butorac said Hoang and the other man had bullied Nguyen. She said he also suffered from mental illness and his brain was damaged during a car crash in his native Vietnam. A defense expert testified at a previous hearing that Hoang had an IQ of 66.

Nguyen turned himself into authorities the day of the shooting. He is scheduled to be sentenced on March 21 and faces up to life in prison.

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