The victim has not been identified. Police said he worked at a nearby Chinese restaurant and was last seen leaving the shopping center on foot on Wednesday.
Shoppers were in disbelief that the shooting happened in their community.
"Kind of scared me right now because this is Irvine, doesn't happen a lot in Irvine," said Irvine resident Steve Lee.
Irvine has been rated one of America's safest cities.
Officers and blood hounds checked the area Wednesday night, but so far, no one has been arrested.
The suspect is believed to be in his mid 20s, about 5 feet 6 inches tall, and was last seen wearing a black hooded sweatshirt, police said.
Anyone with information is urged to call Irvine police at (949) 724-7168.
City News Service contributed to this story.
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