The manhunt for a masked gunman who shot dead a US healthcare leader in a brazen morning attack outside a Manhattan hotel has intensified.
UnitedHealthcare chief executive Brian Thompson, 50, was killed in a dawn ambush on Wednesday as he walked to the company's annual investor conference at a Hilton in Midtown.
The killer, wearing a face mask, approached Mr Thompson outside the hotel from behind and opened fire several times, hitting him in the back and leg before the weapon jammed.
The New York Police Department released an image of the suspect at a nearby Starbucks just minutes before the 6.45 EST (11.45GMT) attack close to Times Square.
Although he is masked in the picture, his eyes and part of his nose can be seen - with investigators hoping they can use facial recognition software to identify him, CBS reported.
Police are also testing three bullet casings and three live rounds found at the scene for DNA, as well as trawling through a discarded mobile phone from the alleyway through which the gunman fled.
The gunman’s escape was captured on CCTV as he fled across a nearby pedestrian plaza, before disappearing on a bike into Central Park.
Officers have used drones, helicopters and dogs in an intense search, but the killer's whereabouts remain unknown.
New York City Police Department (NYPD) 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.
"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," NYPD chief of detectives Joseph Kenny added.
Police issued several surveillance images of the man, who wore a hooded jacket and a mask that concealed most of his face.
The police department offered a reward of up to 10,000 dollars for information leading to an arrest and conviction.
Mr Thompson's wife, Paulette Thompson, told NBC News that he told her "there were some people that had been threatening him".
She did not have details but suggested the threats may have involved issues with insurance coverage.
"Brian was a highly respected colleague and friend to all who worked with him," the insurer's Minnetonka, Minnesota-based parent company, UnitedHealth Group Inc, said in a statement.
"We are working closely with the New York Police Department and ask for your patience and understanding during this difficult time."
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.
New York officers were also searching Mr Thompson's hotel room, interviewing his UnitedHealthcare colleagues and reviewing his social media.
Police initially said the gunman rode into Central Park on a bicycle from the city's bike-share programme, CitiBike.
But 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.
Health care 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 programmes.
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," the Democrat wrote.
