CHICAGO (CBS) — A fallen Chicago police officer was among 22 public safety officers honored for their bravery Wednesday, during a ceremony at the White House.

The mother and fiancée of Officer Clifton Lewis accepted his posthumous Medal of Valor, awarded by Vice President Joe Biden and Attorney General Eric Holder.

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“Maxine, our heart aches for you, mom. We know that no child should ever pre-decease a parent,” Biden told Lewis’ mother.

He also said he admired the courage of Lewis’ fiancée.

“We owe you,” he said.

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On Dec. 29, 2011, Lewis was moonlighting as a security guard at a neighborhood convenience store, when robbers came in. Lewis was shot four times as two masked men tried to rob the store.

Assistant Attorney General Carol Mason said Lewis gave his life to protect others.

“Officer Lewis announced that he was an officer, and moved to shield other employees as he drew his weapon. Officer Lewis was struck four times by the assailants’ bullets. He died after protecting the store’s employees and customers, none of whom were harmed,” she said.

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Also among those honored were two officers from Oak Creek, Wisconsin, who stopped a shooting rampage at a Sikh temple. One of the officers was seriously wounded in the shooting spree. Police shot and killed 40-year-old Wade Michael Page after he killed six people at the temple.