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The gunman who fatally shot UnitedHealth Group CEO Brian Thompson early Wednesday used a silencer on his firearm, sources say.

Thompson, 50, was shot as he walked past a hotel in Midtown Manhattan at 6:45 a.m. Wednesday. A woman who witnessed the shooting right in front of her was not harmed.

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NYPD

Photo may have been deleted

Police released surveillance images of the suspect and video recorded outside the New York Hilton Midtown Hotel on the Avenue of the Americas near 54th street. The video shows Thompson wearing a blue jacket and dark pants walking past the hotel.

A man wearing a black hoodie and a grey backpack approached Thompson from behind and fired a handgun equipped with a silencer. According to firearms experts, the gunman racked the gun after each shot because he used subsonic ammunition which caused the gun to jam.

Afterwards, the man ran across the street and fled the scene on an electric Citibike.

Thompson earned $10 million a year as CEO of UnitedHealth Group. He also earned a $20 million bonus.

According to reports, Thompson and UnitedHealthcare Chairman Stephen Helmsley were under investigation by the DOJ for selling over $114 million in company stock last year. Thompson reportedly sold $12 million in UnitedHealth stock worth $521 a share at the time. While Helmsley sold over $102 million in stock.

Thompson’s wife, Paulette Thompson, told NBC News he had been receiving “some threats” but she didn’t know the details.

“I just know that he said there were some people that had been threatening him,” she said. “I can’t really give a thoughtful response right now. I just found this out and I’m trying to console my children,” she added.

His family said Thompson was a “good father” to his 2 children.

The gunman is still on the loose. New York City officials are considering canceling the Rockefeller Center Christmas Tree lighting ceremony scheduled for tonight.

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