The New York Police Department on Saturday released two new photos of a person being sought in the killing of UnitedHealthcare CEO Brian Thompson.

The photos are the latest in a series by the NYPD of the same individual wanted for questioning in Wednesday’s killing.

The person can be seen in one of the photos through the partition of what appears to be a New York City taxi, wearing a blue medical mask and a black hoodie.

The other photo, taken from inside a car, shows the man outside the window walking alongside the vehicle while wearing the same blue mask and a dark-colored puffer jacket with the hood pulled over his head.

The NYPD has said investigators have been able to track some of his movements by taxi.

As the investigation into Thompson’s killing and the manhunt for the gunman carried into Saturday, three sources familiar with the probe told NBC News there was still no identification of the person of interest.

A combined $60,000 in reward money is being offered by the FBI, Crime Stoppers and the NYPD for information leading to the arrest of the gunman.

Thompson was gunned down outside the New York Hilton Midtown hotel as he was on his way to UnitedHealth Group’s investor conference Wednesday morning, officials have said.

Thompson was shot at least once in the back and once in the right calf. He was not traveling with security.

“Based on the evidence we have so far, it does appear the victim was specifically targeted,” Joseph Kenny, NYPD chief of detectives, said earlier in the week. “But at this point, we do not know why.”

New York Police Commissioner Jessica Tisch said Wednesday it was a “premeditated, preplanned targeted attack.”

Shell casings found at the scene had the words “deny,” “delay” and “depose” written on them, police said.

Police also found a gray backpack in Central Park that the person of interest was said to be carrying at the time of the slaying. Officials were looking into whether it was in fact the same bag, two senior law enforcement officials told NBC News.

A cellphone was found by police near the scene, and investigators are trying to use it to learn more about the man’s contacts and his movement, two sources familiar with the probe said.

Four sources familiar with the investigation told NBC News on Saturday that no gun was found in the backpack. Three sources said there was a jacket in the bag, but it remains unclear whether it is the jacket the gunman wore at the time of the shooting.

Authorities believe the man being sought in connection with the killing may have left the state.

Kenny told reporters that video shows the man riding a bike in Central Park, then taking a taxi to the Port Authority bus station close to the George Washington Bridge.

Investigators are looking for additional video to determine if he got on a bus from there, and if so which one.

Police believe he may have traveled to New York City from Atlanta last month by Greyhound bus, three senior law enforcement officials familiar with the case told NBC News. The bus arrived in New York on Nov. 24, after making several stops along the way, they said.

Officials in New York are looking into whether they can find a name used for the Nov. 24 trip, and both Atlanta police and Greyhound are assisting in the probe.

While in New York, the man stayed at a hostel on Manhattan’s Upper West Side, the NYPD said at a Friday briefing. Authorities are working to determine whether he paid in cash and used a fake ID to rent a room there.

Roommates at the hostel said he kept his mask on the entire time, even while eating, only pulling it down to take a bite, the NYPD said.

Thompson’s wife, Paulette Thompson, told NBC News on Wednesday that her husband had been receiving threats, but she was unclear of their nature.

“There had been some threats,” she said. “Basically, I don’t know, a lack of coverage? I don’t know details. I just know that he said there were some people that had been threatening him.”