UnitedHealthcare CEO Brian Thompson was murdered on Wednesday in a targeted killing in Manhattan, New York. As police continue to piece together key evidence and clues, a manhunt has been launched to find the shooter, who has been photographed as smiling in the latest surveillance photo.

An image released by the New York Police Department shows a man, dressed in a hoodie, as the "person of interest" in Brian Thompson's killing.

Manhattan Shooting - What We Know

The alleged gunman was captured in CCTV cameras after sharing a brief yet flirtatious moment with a female staffer at a hostel in New York.

Speaking to CNN, the official stated that the female employee asked the man to lower his mask and "give a big smile" to her.

"That little flirtation between the two of them, in some good-humored way, actually yielded what is so far the most significant clue to identifying him," the official further told CNN.

These images of the shooter are now some of the key pieces of evidence in the manhunt. The shooter remains on the run after gunning down the healthcare executive on Wednesday morning in Midtown Manhattan.

Along with this surveillance image of the alleged gunman, it was also discovered that the three bullets that struck Thompson had been scribbled on with permanent marker with the words - "deny", "defend" and "depose".

As per an AP report, the words were written on the casing of the bullets in permanent marker and were found at the crime scene.

The messages found on the bullet casing mimic a common phrase "delay, deny, defend,” used by lawyers and insurance industry critics to describe tactics used by insurers to avoid paying claims.

The phrase is also related to a book with a similar title - Delay, Deny, Defend: Why Insurance Companies Don't Pay Claims and What You Can Do About - published in 2010 by Rutgers Law professor Jay M. Feinman

The casings also reflect the mentality of Health insurers such as UnitedHealthcare which have been at the centre of criticism from doctors and patients for denying claims.

UnitedHealthcare provides coverage for over 49 million Americans and brought in more than $281 billion in revenue in 2023 as one of the nation’s largest health insurers.

Accompanying these bullet casings and a surveillance photo is frame footage of the alleged attacker stopping at a Starbucks before the shooting occurred.