UnitedHealthcare CEO assassin left message behind to 'make a statement' or 'throw off police': Detectives

Messages etched onto bullet casings by the suspect who killed UnitedHealthcare CEO Brian Thompson on Wednesday were "left behind to make a statement," a New York Police Department detective told Fox News Digital. 

Police sources told the New York Post that the words "deny," "depose" and "defend" were written on the live rounds and casings left behind by the assassin after the shooting. Each bullet and casing had just one word written on it.

"Clearly intentionally left to make a statement," the detective said on Thursday. "This will help identify a motive and eventually the suspect."

The words could be derived from "Delay. Deny. Defend: Why Insurance Companies Don't Pay Claims and What You Can Do About It," a book published by Jay Feinman in 2010. Fox News Digital could not reach Feinman or the book's publisher, Delden Press, for comment at press time. 

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This undated photo provided by UnitedHealth Group shows UnitedHealthcare chief executive officer Brian Thompson. (AP Photo/UnitedHealth Group)

Thompson's wife, Pauline, has said that her husband had been receiving death threats. 

"There had been some threats," Thompson's wife told NBC News."Basically, I don't know, a lack of [health care] coverage? I don't know details. I just know that he said there were some people that had been threatening him."

Alternatively, former Washington, D.C. homicide detective Ted Williams told Fox News Digital, the message could have been left behind to "throw investigators off."

In a shocking video obtained by Fox News Digital, Thompson is seen walking down a New York City sidewalk when a masked man wearing a black hooded jacket and a backpack walks up behind him and raises a handgun.

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A surveillance image released by the NYPD shows the suspect in the shooting death of United Healthcare CEO, Brian Thompson on Wednesday, December 4, 2024. (NYPD Crimestoppers)

The culprit fired several shots. At one point, the gun appeared to jam. The assailant then appeared to smack the gun on the side while walking toward the victim, who was attempting to get away.

The NYPD detective, who asked not to be named, also noted that "the silencer [used by the assassin] appears to be one that was made specifically for this incident, which explains the jamming… and rechambering the failed rounds."

Following the shooting, the suspect walked between two vehicles, got onto a bike then disappeared into Central Park, the NYPD said.

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Scene near the Hilton Hotel in Midtown Manhattan, NY where UnitedHealthcare CEO Brian Thompson was killed on Wednesday, December 4, 2024. (Julia Bonavita/Fox News Digital)

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Investigators hope accompanying evidence left behind will help identify him, including a cellphone discovered in an alleyway near the hotel where the shooting occurred, as well as a cup in a trash can at a nearby Starbucks. 

"They look at everything and everybody and put the timelines and evidence together piece by piece and very methodically," the detective said. "Hopefully he left DNA."

Fox News Digital's Christina Shaw contributed to this report.