What we know about NYC killing of healthcare executive

The manhunt for a suspect who gunned down a healthcare chief executive in New York is now entering its third day, with police chasing several different leads.

UnitedHealthcare boss Brian Thompson, 50, was fatally shot in the back on Wednesday morning outside the Hilton hotel in Midtown Manhattan.

Police say Thompson was targeted in a pre-planned killing, for which they do not yet have a motive.

Investigators are also using newly released surveillance photos and bullet casings with cryptic messages written on them to track down the suspect.

Here's what we know about the suspect and the investigation.

Police are working with "a lot of leads", said former FBI special agent Michael Tabman.

Police have put together more than 200 images of the suspect from his arrival in New York until he fled Midtown Manhattan after shooting Thompson, according to the BBC's US partner CBS News.

Police have also shared two images - the clearest ones so far - of the suspect, one of which shows him smiling with his mask pulled down.

A hostel receptionist reportedly told police that the photo was taken when she asked him to show his face, in a flirtatious moment.

The man was staying at the hostel on the Upper West Side in New York, where he reportedly used a fake New Jersey license as identification. Police say they have executed a search warrant at the hostel.

Officials are also attempting to make use of DNA evidence, including a water bottle and candy wrapper from the crime scene - as well as a Starbucks coffee cup - that they believe are linked to the suspect.

A mobile phone was also discovered in an alley along the suspect's escape route.

Police believe the suspect arrived in New York as early as 10 days before the shooting took place.

Law enforcement sources told US media that a surveillance camera at the Port Authority Bus Terminal in the city shows the suspect arriving by bus in New York on 24 November.

Investigators believe the suspect took a bus that originated in Atlanta, Georgia, to New York days before the shooting, CBS reports, citing a person briefed on the investigation. It's unclear whether the person got on the bus at Atlanta or later during a stop.

The suspect then checked into the Upper West Side hostel after arriving in the city.

The hostel is near the Frederick Douglas housing project, where police say surveillance video showed the suspect outside at approximately 05:00 the morning of the crime.

The shooting took place at about 06:45 EST (11:45 GMT) in a busy part of Manhattan close to Times Square and Central Park. Thompson had been scheduled to speak at an investor conference later in the day.

According to police, the suspect - who was clad in a black face mask and light brown or cream-coloured jacket - appeared to be waiting for Thompson for five minutes outside the Hilton hotel where he was expected to speak.

Thompson, who arrived on foot, was shot in the back and leg, and was pronounced dead about half an hour later at a local hospital.

New York Police Department (NYPD) Chief of Detectives Joseph Kenny has revealed that the suspect's weapon appeared to jam, but that he was able to quickly fix it and keep shooting.

CCTV footage appears to show the gunman had fitted a suppressor, also known as a silencer, to his pistol, BBC Verify has established.

Investigators reportedly believe the firearm is a BT Station Six 9, a weapon which is marketed as tracing its roots back to pistols used in World War Two.

Police have reportedly visited gun stores in Connecticut to try to determine where the weapon was purchased.

After the shooting, video shows the suspect fleeing the scene on foot. Officials say he later got on an e-bike, which he rode toward Central Park, where he was last seen.

Investigators have so far not identified a motive in the killing, but they are focusing in part on words written in Sharpie on bullet casings discovered at the scene of the crime.

The words "deny," "defend" and "depose" were discovered on the casings.

Investigators believe this could be a reference to the "three D's of insurance" - a known reference made by opponents of the industry.

The terms refer to tactics used by insurance companies to refuse payment claims by patients in America's complicated and mostly privately run healthcare system.

The words resemble - but are not exactly the same as – the title of a book called Delay, Deny, Defend: Why Insurance Companies Don't Pay Claims and What You Can Do About It.

The book, published in 2010, was written by Jay Feinman, a legal scholar at Rutgers University in New Jersey. It's billed as an exposé of the insurance industry and a how-to guide for Americans on how to navigate the system.

Professor Feinman declined to comment when the BBC contacted him.

Thompson joined UnitedHealth, the biggest private insurer in the US, from accountancy firm PricewaterhouseCoopers in 2004.

He rose through the ranks and became CEO in 2021, leading the company through some very profitable years.

In an interview with MSNBC, Thompson's wife said that there had "been some threats" against him earlier, although she was unable to provide details.

"I just know that he said there were some people that had been threatening him," she said.

According to police in Thompson's hometown of Maple Grove, Minnesota, there had previously been one suspicious incident at his home in 2018.

The incident was cleared with no criminal activity detected. No additional details were provided.