The search for the suspected assassin in the brazen slaying of UnitedHealthcare CEO Brian Thompson in Manhattan enters its third day, as police revealed clues to the killer’s identity but many facts about the shocking shooting remain unknown.

Thompson was fatally shot outside a Hilton hotel in midtown Manhattan around 6:40 a.m. ET on Wednesday, shortly before he was scheduled to speak at the company’s annual investor conference.

The killer, a person dressed in black and wearing a backpack who was familiar with firearms, waited for Thompson outside the hotel, shot him with a pistol that appeared to be equipped with a silencer and fled through a nearby alley to an e-bike and then into Central Park.

“It appears from the video that he is proficient with firearms because he was able to clear the malfunctions fairly quickly,” NYPD Chief Detective Joseph Kenny said.

A manhunt ensued immediately and is ongoing, with police tapping the city’s vast network of public and private cameras and releasing information throughout the week.

On Thursday, police released images believed to show the suspect at a hostel on the city’s Upper West Side, where he appeared to flirt with the receptionist and reveal his face. According to a report from CNN, he used a fake New Jersey driver’s license to check in.

Additionally, police said they believe the suspect arrived in New York on a Greyhound bus from Atlanta, Georgia – although it is unclear where exactly the suspect boarded. At the crime scene, police found a cellphone, a water bottle and a protein bar wrapper that they believe the killer may have discarded.

While the motive for the killing remains unknown, Johnson’s death has touched a sensitive nerve among many Americans about their often horrific and exploitative dealings with the for-profit U.S. health care industry. Conjectures about the motive for the killing were reinforced by the words “deny,” “depose,” and “defend” scrawled in magic pen on the balls.

On social media, Thompson’s death sparked an outpouring of anger toward the private health insurance industry he represented, alarming researchers about political violence and making company managers nervous.

“Now the norms of violence are spreading into the commercial sector,” said Robert Pape, director of the University of Chicago’s Security and Threats Project. “That’s what I saw when I saw that.”

Many compared Johnson’s killing to the denial of treatment by health insurers – charts of denial rates went viral, and corporate security firms noted a significant increase in violence over the past five years. If true, this increase would reflect a rise in violent political threats that researchers say began in the first Trump administration.

“There is a lot of pent-up outrage at this company and other companies that act as an intermediary between a patient and their doctor or hospital,” said Wendell Potter, a former Cigna vice president turned industry critic. told the Minnesota Star Tribune.

As Americans shared stories of stinging treatment by private insurers, Anthem Blue Cross Blue Shield plans in Connecticut, New York and Missouri announced they would no longer pay for anesthesia if a surgery exceeds a certain amount of time.

Online, the decision was tied to general anger at the insurance industry sparked by Thompson’s death. Given that backlash and doctors’ alarm, the insurer reversed the decision on Thursday, citing “significant, widespread misinformation” about the insurance change.

The murder has also unsettled company executives. It is common for company leaders to receive threats because they are essentially the human face of a company. Thompson’s wife, Paulette, told NBC News he had received threats in the past.

Thompson was CEO of UnitedHealth Group’s insurance division, a highly paid executive who earned $10 million in annual compensation. UnitedHealth is one of the largest companies in the world with a market capitalization of $533 billion, making it larger than household names like Mastercard and ExxonMobil.

UnitedHealthcare has been criticized for denying care to vulnerable, chronically ill and elderly patients; Using artificial intelligence to systematically and falsely reject claims; is the subject of federal monopoly and insider trading investigations; and was the subject of discussion in Congress due to serious disruptions caused by a cyberattack this year.

Thompson is a 50-year-old chartered accountant who has reportedly kept a low profile in public. He is survived by two sons and his wife, all of whom live in Maple Grove, Minnesota, where the company is headquartered.

The Associated Press contributed reporting