New York police have released the first unmasked photographs of a person of interest as they continue to investigate the shooting death of a senior executive at a US health insurance company.
Police have described the killing of UnitedHealthcare chief executive Brian Thompson, 50, as a "premeditated, targeted attack".
He was shot out the front of a Hilton hotel in New York City on Wednesday morning, local time, as he was arriving to attend an investor conference.
On Thursday, multiple US media outlets, including the Associated Press, quoted unnamed officials saying the ammunition used to shoot Mr Thompson had the words "deny," "defend" and "depose" written on them.
The words on the ammunition may have been a reference to strategies insurance companies allegedly use to try to avoid paying claims.
Investigators recovered several shell casings from outside the hotel, and a mobile phone from the alleyway through which the shooter fled, NYPD Chief of Detectives Joseph Kenny said earlier.
The killing and the shooter's movements in the minutes before and afterwards were captured on some of the multitudes of security cameras present in that part of the city.
The reason behind the ambush killing of Mr Thompson has remained unknown, but police on Wednesday said the shooting appeared to be targeted.
Security camera video showed the killer approach Mr Thompson from behind, level his pistol and fire several shots, barely pausing to clear a gun jam while the health executive tumbled to the pavement.
"Many people passed the suspect, but he appeared to wait for his intended target," New York Police Commissioner Jessica Tisch said.
The shooter was last seen riding an e-bike into Central Park.
Widow says UnitedHealth CEO received threats
Mr Thompson, who has two sons, had been working for UnitedHealthcare since 2004 and served as its chief executive for more than three years.
The insurer's parent company, UnitedHealth Group Inc., was holding its annual meeting with investors in New York to update Wall Street on the company's direction and expectations for the coming year.
The company ended the conference early after Mr Thompson's death.
"Brian was a highly respected colleague and friend to all who worked with him," UnitedHealth Group 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."
Mr Thompson's wife, Paulette Thompson, told NBC News on Thursday that he had previously told her "there were some people that had been threatening him".
She did not provide details but suggested the threats may have involved issues with insurance coverage.
ABC/AP
