As the search for UnitedHealthcare CEO Brian Thompson’s killer continues, New York police released two more photos of the suspected shooter late Saturday that appeared to be from a camera mounted in a taxi.

The first shows him outside the vehicle and the second shows him looking through the partition between the back seat and the front of the cab. In both cases, his face is partially obscured by a blue medical-style mask.

Police have traced the shooter’s steps through surveillance video and apparently left the city by bus shortly after the shooting outside the New York Hilton Midtown on Wednesday morning. He was seen on video about 45 minutes later at a downtown bus stop, said NYPD Chief Detective Joseph Kenny.

As the high-profile search expanded across state lines, the FBI announced late Friday that it was offering a $50,000 reward for information leading to an arrest and conviction, in addition to the reward of up to $10,000 , which the NYPD has suspended. Police believe the suspect acted alone.

The police don’t know who he is, where he is or why he did it. However, they are confident that it was a targeted attack and not a random act. And New York City Mayor Eric Adams stressed Saturday that “the net is getting tighter.”

Using drones, police officers combing Central Park found a backpack believed to have been discarded by Thompson’s killer during his escape. NBC News reported, citing two sources, that there was counterfeit money from the board game Monopoly in the backpack.

Aside from the obviously targeted nature of the attack, the words “delay,” “denial,” and possibly “cancellation” were written on bullet casings found after Thompson’s murder. Such evidence raises the possibility that the motive is related to the health care industry’s routine denial of payment for medical services to many Americans.

Healthcare debt has emerged as a leading cause of bankruptcies in the US, while for-profit health insurers such as UnitedHealthcare are among the richest companies in the country. Thompson, 50, who lived near UnitedHealthcare’s headquarters in Minnesota, had an annual salary of $10 million before he was shot as he prepared to attend a meeting with the company’s investors.

Thompson’s survivors include a wife and two sons, now 19 and 16 years old.