His victim was sprawled dying on the pavement and witnesses were already calling the police, but the gunman seemed glacially cool after shooting health insurance company boss Brian Thompson.
He walked calmly away from the scene of the crime, only breaking into a jog as he crossed 54th Street, the road next to the Hilton Hotel side entrance where he’d ambushed Mr Thompson.
He then headed down a passageway known as the ‘Ziegfeld Alleyway’, which was almost immediately opposite. It led him north to 55th Street where he turned right and was quickly on busy Sixth Avenue in the heart of Manhattan’s Midtown.
An Uber driver who had witnessed the shooting snapped a photo of the hooded assassin’s back as he made his getaway at around 6.46am on Wednesday.
As the manhunt continues for the killer of the chief executive of United Healthcare, America’s biggest health insurer, investigators will be concentrating on what he did after he killed Mr Thompson.
How did he manage to disappear in a packed city teeming with surveillance cameras as easily as he’d first appeared, moving stealthily out from behind a parked car and, with the ease of a professional, shooting his target in the back as he was headed for his multi-billion-dollar company’s annual investors conference?
Some of those CCTV cameras have thrown up a few clues and one established that the killer had swiftly hopped on to an electric bike and ridden north up Sixth Avenue towards Central Park.
Police reportedly no longer believe he used a Citi Bike, similar to one of London’s so-called Boris Bikes. He would have had to hire it by providing credit card details and a phone number, thereby revealing his identity, which makes it unlikely.
The gunman was last seen on West 85th Street, 13 minutes after he fatally shot Brian Thompson
The unidentified man who shot and killed the UnitedHealthcare CEO was spotted at a nearby Starbucks’ counter in the moments before he opened fire
Investigators have speculated that the gunman may have been carrying an e-bike battery to ensure the vehicle he used for his getaway didn’t run out of juice.
Whatever the truth, by the time he got on the bike, he had provided police with a potentially crucial lead by dropping a mobile phone in the alley – he had been spotted on CCTV speaking on a phone just 15 minutes before the murder, as he walked to the Hilton.
Did he get rid of it because he feared it would allow police to trace his movements, or did he drop it by mistake? It appears to be a pre-paid ‘burner phone’, which can be bought with cash and so the purchaser’s identity cannot be easily discovered.
However, if police can hack into its system, it could reveal who he was talking to on it. And like an empty water bottle that was recovered from a nearby bin, it is also being tested for fingerprints.
We now know the shooter arrived in the city on a Greyhound bus ten days before the shooting and had plenty of time to scout out his options in Manhattan’s urban jungle.
So he may have spotted that New York’s most famous park is rather less well covered by CCTV cameras than surrounding streets. The perfect place, perhaps, to get rid of compromising evidence like the gun and rearrange his appearance.
What is clear is that he moved quickly. Police say the suspect was seen riding the bike into Central Park on Centre Drive at 6.48am – just a few minutes after the shooting.
Centre Drive is a historic carriage path that runs up the centre of the southernmost section of the 843-acre park. From there, the gunman could have turned into any number of tree-lined paths that would have been largely empty.
Brian Thompson, 50, had been slated to speak at an investor meeting at the Hilton Hotel on the Wednesday morning when he was killed
On Wednesday afternoon, flags outside the UnitedHealthcare headquarters in Minnetonka, Minnesota were lowered
However, given where and when he was later spotted on CCTV, he probably turned left into West Drive, part of the park’s main circular thoroughfare and the most popular route for cyclists.
It would have involved him cycling against the flow of the one-way system and so potentially getting stopped by police, but it’s unlikely there would have been too many of them in the park at that hour.
Central Park is thickly wooded in many places, which would have afforded the killer the perfect opportunity to change clothes, if he was carrying any.
A CBS News report screened a surveillance video showing someone police believe could be the gunman cycling down 85th Street – 26 blocks north of where he entered the park – at 6.59am.
CBS said investigators believe he’d come out of the park somewhere between 70th and 80th streets and ridden up Central Park West, the street that runs along the park’s western edge.
From the photo, it appears he has put on a cap and is no longer wearing the backpack police believe he may have discarded in the park and could contain the murder weapon. He was by then in the heart of the Upper West Side, the smart neighbourhood where he had reportedly been staying since arriving in New York.
After that final turn on to 85th Street, there have been, to date, no further sightings of the gunman. His options from there are myriad. He could have used that final phone call before the murder to arrange for someone to pick him up in a car.
To get from where he was last seen next to the park to the George Washington Bridge would involve a drive of less than seven miles. Then he would have been out of New York and into New Jersey – and straight on the Interstate 95 highway that runs south as far as Miami, Florida, and north right up to the Canadian border a nine-hour drive away.
The assassin fled the scene on a bicycle and is believed to have escaped to Central Park, leading the NYPD to offer a $10,000 reward
Thompson was fatally shot in the chest at 6.45am outside the Sheraton Hotel in New York City
It certainly seems preferable to hunkering down in New York, where the intensive hunt for him has involved helicopters, drones and dogs.
For someone who police think had been in New York since he was seen on CCTV getting off a bus that originated in Atlanta, Georgia, at 9pm on November 24, he attracted very little attention.
No doubt it helped that he was hiding his face under a ski mask and hooded top – certainly not unusual in New York given lingering Covid fears and the current chilly weather.
For most of the time, the gunman stayed at the HI New York City Hostel in the Upper West Side. He used a fake New Jersey driving licence as ID and paid his bill in cash.
Guests share a bunk-bed dormitory and communal kitchen. The gunman wore a mask even indoors and kept to himself, though not to the extent that he aroused suspicion.
However, in a crucial break for investigators, a flirtatious female receptionist at the front desk persuaded him to pull down his mask so she could see his ‘pretty smile’. He complied, providing police with the best images of him so far. The gunman checked out on November 29, only to check back in on November 30.
Police believe he used a highly unusual firearm – a 9mm ‘covert’ pistol with a built-in silencer called a BT Station Six 9 which is based on a World War II British bolt-action spy gun, the Welrod. Investigators are following up reports that one was recently sold in Connecticut.
On the day of the shooting, he was first spotted on CCTV at 5am near the Frederick Douglass Housing Project on the Upper West Side.
Authorities released surveillance photos of the alleged gunman they believe fatally shot Brian Thompson
NYPD officers at the scene of the shooting near W. 54th St. and 6th Avenue. A witness said the shooter killed Thompson from point blank range before fleeing on a bicycle
At around 6.15am he was caught on camera emerging from a subway station in Midtown Manhattan not far from the Hilton Hotel. Two minutes later, he was photographed in a branch of Starbucks, using cash to buy two bottles of water, a cup of coffee and two energy bars.
Experts say such a last minute stop-off – in which he appears not to be wearing gloves – indicates the gunman is not a professional hitman.
Police say they found unspecified ‘forensic evidence’ in Starbucks and that items recovered there – most likely the paper cup and wrappers – were being analysed for DNA.
After talking to someone on the phone at 6.30am as he walked to the Hilton, the gunman took up position outside just five minutes before his victim emerged from his hotel across the street.
The convention Mr Thompson was due to address in the Hilton’s ballroom wasn’t due to start for more than an hour. How the killer knew so precisely where his target would be, and when, is just another mystery that surely won’t be solved until he is identified and captured.