The masked gunman who stalked and killed the leader of one of the largest US health insurance companies on a Manhattan sidewalk used ammunition emblazoned with the words “deny”, “defend” and “depose”, a law enforcement official said on Thursday.
The official was not authorised to publicly discuss details of the ongoing investigation and spoke to The Associated Press on the condition of anonymity.
UnitedHealthcare chief executive Brian Thompson, 50, died in a dawn ambush on Wednesday as he walked to the company’s annual investor conference at a Hilton in Midtown, blocks from tourist draws like Radio City Music Hall and the Museum of Modern Art.
The words on the ammunition may have been a reference to strategies insurance companies use to try to avoid paying claims.
The killing, and the gunman’s movements in the minutes before and afterwards, were captured on the multitudes of security cameras present in that part of the city.
Based on surveillance video and evidence from the scene, investigators believe that the gunman had some prior firearms training and experience with guns at least, and the weapon was equipped with a silencer, the official said.
Investigators are also looking into whether the suspect had pre-positioned a bike as part of an escape plan.
The suspect fled on a bike and he was last seen riding into Central Park.
Authorities were running DNA and fingerprint analysis on items found nearby, including a water bottle that they believe the suspect may have discarded, the official said.
Security camera video showed the gunman approach Mr Thompson from behind, level his pistol and fire several shots, barely pausing to clear a brief gun jam while the health executive tumbled to the pavement.
Other security cameras captured the initial stages of the gunman’s escape.
He was seen fleeing the block across a pedestrian plaza, then escaping on a bicycle into Central Park, where he vanished.
Police used drones, helicopters and dogs in an intense search, but the killer’s whereabouts remained unknown late into the night.
New York City Police Commissioner Jessica Tisch said that while investigators had not yet established a motive, the shooting was no random act of violence.
“Many people passed the suspect, but he appeared to wait for his intended target,” Ms Tisch said at a news conference on Wednesday.
NYPD chief of detectives Joseph Kenny said: “From watching the video, it does seem that he’s proficient in the use of firearms as he was able to clear the malfunctions pretty quickly.”
Police have issued several surveillance images of the man. He wore a hooded jacket and a mask that concealed most of his face, which wouldn’t have attracted attention on a cold winter day.
Some of the photos were taken at a Starbucks coffee shop shortly before the shooting.
The police department offered a reward of up to 10,000 dollars (£7,832) for information leading to an arrest and conviction.
The insurer’s parent company, UnitedHealth Group Inc, said in a statement: “Brian was a highly respected colleague and friend to all who worked with him.
“We are working closely with the New York Police Department and ask for your patience and understanding during this difficult time.”
Mr Thompson’s wife, Paulette Thompson, told NBC News that her husband told her “there were some people that had been threatening him”.
She didn’t have details but suggested the threats may have involved issues with insurance coverage.
Eric Werner, the police chief in the Minneapolis suburb where Mr Thompson lived, said his department had not received any reports of threats against the executive.
Investigators recovered several 9mm shell casings from outside the hotel and a mobile phone from the alleyway through which the gunman fled.
They were also searching Mr Thompson’s hotel room, interviewing his UnitedHealthcare colleagues and reviewing his social media, Mr Kenny said.
Police initially said the gunman rode into Central Park on a bicycle from the city’s bike-share programme, CitiBike.
However, a spokesperson for the programme’s operator, Lyft, said police officials informed the company on Wednesday afternoon that the bike was not from the CitiBike fleet.
Healthcare giant UnitedHealth Group was holding its annual meeting with investors to update Wall Street on the company’s direction and expectations for the coming year.
The company ended the conference early in the wake of Mr Thompson’s death.
Mr Thompson, a father of two sons, had been with the company since 2004 and served as chief executive for more than three years.
UnitedHealthcare is the largest provider of Medicare advantage plans in the US and manages health insurance coverage for employers and state and federally funded Medicaid programs.
Minnesota Governor Tim Walz posted on the social platform X that the state is “sending our prayers to Brian’s family and the UnitedHealthcare team”.
“This is horrifying news and a terrible loss for the business and health care community in Minnesota,” he wrote.