Flirty receptionist asked Brian Thompson suspect ‘can I see your pretty smile?’ before he dropped mask in ‘key clue’

A FLIRTY receptionist reportedly asked healthcare CEO Brian Thompson's suspected killer "can I see your pretty smile?"

The chat up line has given cops the most "significant" clue in hunting down the alleged shooter with the man dropping his mask and CCTV filming his face.

Cops released an image of the suspect beaming at the desk clerk in the HI New York City Hostel when he checked in four days before the brazen execution in Midtown Manhattan.

NYPD Deputy Commissioner for Intelligence and Counter-terrorism John Miller said the receptionist told cops she asked to "see his pretty smile", .

The suspect then pulled down his mask and grinned at the woman with a CCTV camera above the desk catching the moment.

Miller said: "They were having a flirtatious moment and he pulls it down and he gives a big smile and that one informal moment between two human beings remains at this moment the most significant clue to date in this whole case."

Officers are hunting the suspected gunman, whose face was carefully masked in almost every shot captured on CCTV.

But the suspect slipped up and pulled down the covering as he flirted with the receptionist giving law enforcement his face.

It's one of a number of images released by police of the man unmasked at the hostel's desk and a Starbucks he visited prior to the shooting as they desperately try to track him down.

NYPD and FBI agents searched the hostel on Amsterdam Avenue, Upper West Side, and found the major clue captured by cameras when he checked in on November 30.

Police believe he first checked in on November 24 and then left on the 29th, before returning on the 30th.

The suspect used a fake New Jersey driver's licence as he sought to hide his identity.

The CCTV snap shows the suspect wearing a similar coat to that worn by the shooter.

Cops tracked him to the hostel after they found other CCTV footage of him in the area at 5am on Wednesday - just an hour before he's believed to have shot the UnitedHealthcare CEO.

A search of the hostel room he slept in at about 6.30pm on Wednesday revealed nothing of note, sources said.

He is believed to have stayed in the multi-person room with up to half a dozen other men and wore a mask for most of his stay.

A tourist from Denmark said: “They [roommates] tried to get into the room but they couldn’t because the police said no.

“Some kind of investigation so they were pretty shocked because they shared a room with that person who could be pretty bad.”

The hostel says it is fully cooperating with the probe.

The suspect is believed to have arrived in New York City on November 24 - 10 days before the killing.

He arrived in the city on a Greyhound bus that travelled from Atlanta to New York, but authorities don't know when he boarded it.

The suspect was careful with covering his face as he tried to "become a ghost", a retired NYPD sergeant told CNN.

Felipe Rodriguez said: "He tried to become a ghost, basically, and the ruse that he used was ‘Let me hide in plain sight'."

Rodriguez said he may have fled into Central Park to change his clothing and evade cops.

He said: “He already knows that we’ve already picked up at least his clothing to be able to broadcast over police radio, so what you wanna do is quickly change out of that."

It comes after chilling CCTV footage shows the moment the gunman shot down the victim.

Thompson was ruthlessly shot multiple times in the back and leg just after 6:45am as he walked into the New York Hilton Midtown.

The killer is believed to have used a rare WW2-inspired spy gun that is known for its use by vets to put down large sick animals, like a horse, sources told the .

The gun used by the shooter appears to match a Brugger & Thomet VP9 - inspired by the Welrod pistol - a British gun developed by special forces in WW2.

The B&T VP9 shares an almost identical design, but is meant to be quiet so as not to scare other animals instead of Nazis.

The '9' in the gun's name refers to its 9mm bullets - matching the size of the ammunition cops found at the scene outside the Hilton Hotel.

MYSTERY MOTIVE

No motive has been released yet for the killing, but police believe Thompson was "specifically targeted".

Forensics teams discovered a chilling message left on the bullets the killer used to murder Thompson in cold blood.

The words "deny," "depose," and "defend," were found on live rounds and shell casings at the scene, police sources told the New York Post.

Those words could have been a reference to the book Delay, Deny, Defend, which covered insurance companies and why they refuse to pay claims.

There is speculation the killer could have been a disgruntled patient with UnitedHealthcare exacting some form of revenge.

The book's author, Jay M. Feinman, refused to speak following the murder.

The phrase is also commonly used by lawyers and insurance critics to describe tactics used to avoid paying claims.

It refers to insurers delaying payment, denying a claim and then defending their actions.

Health insurers like UnitedHealthcare have become frequent targets of criticism from doctors and patients for denying claims or complicating access to care.

A $10,000 reward for information related to the killer has been offered by the NYPD.

Police have urged the public to call Crime Stoppers on 1-800-577-TIPS with any information.

TRIBUTES PAID

Meanwhile, Thompson's wife, Paulette, said her husband had been receiving threats in the run-up to his murder.

A fake bomb threat targeting Thompson's home was sent approximately 12 hours after his assassination, as reported by .

It has also been revealed the couple were estranged, with the pair living in separate homes less than a mile apart in suburban Maple Grove, Minnesota.

An emotional Paulette paid tribute to her late husband in a statement.

"Brian was an incredibly loving, generous, talented man who truly lived life to the fullest and touched so many lives," she said.

"Most importantly, Brian was an incredibly loving father to our two sons and will be greatly missed."

Thompson, who had been the CEO of America's largest private health insurer since April 2021, earned a salary of almost $9.9 million.

He was with the company for 20 years and was reportedly under investigation by the Department of Justice at the time of his death.

Thompson, along with fellow execs Stephen Helmsley, Erin McSweeney, and Tom Roos, was facing a DOJ probe after netting a combined $101.5 million from stock sales over four months before the public became aware of a federal antitrust investigation.

On February 16, less than two weeks before news of the probe went public, Thompson exercised stock options and sold shares worth $15.1 million.

Thompson had been assigned an in-house security detail during his trip to New York City, a source said, but that detail was not with him at the time of the shooting.

But a former senior security director at another major insurance company told CNN it is often hard to get executives to accept security even when they are facing threats.

Other healthcare providers have stepped up security for their executives in the wake of Thompson's murder.