The words “deny,” “defend” and “depose” were reportedly discovered by investigators on bullet casings found at the scene where UnitedHealth Group CEO Brian Thompson was fatally shot, police sources told ABC News.

The chilling detail emerged as the suspect remains at large following what NYPD Commissioner Jessica Tisch called a “brazen, targeted attack” during a press conference on Wednesday, December 4.

Thompson, 50, was shot outside New York’s Hilton Midtown Hotel shortly before 6:45 a.m. on Wednesday, December 4th. According to Tisch, the masked gunman was “lying in wait” outside the building. Detective Chief Joseph Kenny added that the shooter appeared to be “proficient” with firearms.

According to ABC News, NYPD investigators are working to determine whether the words found on the casing were intended as a message from the shooting suspect and a clue to his motive.

Thompson was in New York City for an investor conference being held at the hotel, NYPD officials said at a news conference Wednesday morning.

Police said the partially masked suspect fled toward Central Park on an electric Citi bicycle after firing at least three shots at the health care manager, hitting him in the back and leg. NYPD officials confirmed that Thompson was later pronounced dead at a local hospital.

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The suspect was still at large as of Wednesday afternoon. He is described as a light-skinned man wearing a brown or cream-colored jacket, a black face mask, black and white sneakers and carrying a “very distinctive gray backpack,” Kenny said. Police are offering a $10,000 reward for information leading to his capture.

Related: Newly released photos show shooting suspect Brian Thompson’s face as killer remains at large

In a post on Although police did not disclose the location where the images were taken, a law enforcement source said New York Times that the shooter had visited a Starbucks located about two blocks from the crime scene.

Thompson’s wife, Paulette, told NBC News that her husband was threatened before his trip to New York. Thompson, who joined UnitedHealth Group in 2004 and became CEO in 2021, lived in Minnesota with his wife and two children, according to Local Channel2 Now.

UnitedHealth Group, the parent company of UnitedHealthcare, said in a statement that it was “deeply saddened and shocked” by the death of its “esteemed colleague.”

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