The massive pistol used by the gunman who killed UnitedHealthcare CEO Brian Thompson was not in the backpack recovered in Central Park that police believe the assassin ditched during his breakneck escape out of the city, NYPD sources said Saturday.

A few articles of clothing were in the backpack, which are currently being tested for DNA, the sources said.

Word of the contents of the backpack comes as the FBI offered $50,000 for information about the masked gunman and the search for the hooded assassin went national.

“The net is tightening, and we are going to bring this person to justice,” Mayor Adams vowed following a Christmas event sponsored by the Police Athletic League Saturday. “This is a horrific incident in our city and we want to make sure this person is removed from the streets of America, not only on the streets of New York.”

Adams wouldn’t say if the NYPD has identified the CEO shooter, who was photographed smiling at a worker at an Upper West Side hostel where he stayed before the killing.

“We don’t want to release that now,” Adams said when asked if detectives knew the suspect’s name. “If you do you’re basically giving a tip to the person we are seeking and don’t want to give him an upper hand at all.

“Let him continue to believe he can hide behind a mask,” Adams said. “We’ve already revealed his face. We’re going to reveal who he is and bring him to justice.”

For the last four days, detectives have been trying to identify the weapon the gunman used and were hoping the triggerman had kept it in his backpack.

The prevailing theory is that the weapon is a B&T Station 6 bolt action pistol, which is commonly used by veterinarians, police said.

“We’re looking into the possibility that it could of been one of those,” NYPD Chief of Detectives Joseph Kenny said at a press briefing at NYPD headquarters Friday. “It’s a weapon commonly used on farms and ranches so an animal could be put down without a lot of noise.”

The feds late Friday began distributing a wanted poster with the smiling gunman, hours after Kenny said that the suspect may have jumped on an interstate bus at an uptown Port Authority bus terminal within 46 minutes of the shooting.

While Thompson’s killer may have fled the city, the NYPD would still bring him to justice — no matter how long it took, Kenny vowed.

“This isn’t ‘Blue Bloods.’ We’re not going to solve this in 60 minutes,” the Chief of Detectives said as he briefed the press Friday. “We’re painstakingly going through every bit of evidence that we come across. Eventually, when an apprehension is made, we’ll have to present all these facts to a judge and jury. So we’re taking our time, we’re doing it right, making sure we’re going to get justice for this victim and closure for his family.”

The FBI has been involved in the killing since Wednesday, but federal investigators posted the upgraded reward Friday. The NYPD initially offered a $10,000 reward for information.

NYPD detectives, with the help of Port Authority police, managed to track the gunman’s movements from when he first arrived in the city to immediately after the deadly shooting, when he traveled by various means to an uptown bus terminal before vanishing.

“Our detectives are doing a very, very extensive video canvas,” said Kenny. “We’re working from back at the Hilton hotel, from the incident itself all the way to uptown Manhattan.”

The suspect shot Thompson, 50, as he walked to a Hilton hotel on W. 54th St. and Sixth Ave. where he was about to address colleagues and company investors at a conference, police said. The shooting took place just blocks from Radio City Music Hall and Rockefeller Center.

Harrowing surveillance footage shows the man shoot Thompson in the back, then fire three more times, at one point pausing to coolly clear a jam in his pistol, before continuing to fire.

Cops found the words “Deny,” “Delay” and “Depose” written in Sharpie on the bullets — reminiscent of the insurance industry mantra “Deny, Delay, Defend” for delaying claims and maximizing profits — leading police to believe that the killer has a beef with the health insurance industry.

The gunman fled the scene on a bicycle and disappeared into Central Park, but cops picked up his trail when he was later seen walking on 86th St. and Columbus Ave. on the Upper West Side, Kenny said.

According to Kenny, the gunman was finally seen entering a cab that dropped him off near the George Washington Bridge Bus Terminal at 178th St and Broadway — his last known location — around 7:30 a.m., just 45 minutes after the fatal shooting.

“Those buses are interstate buses,” Kenny said. “That’s why we believe he may have left New York City.”

Thompson, a father of two sons who lived in a Minneapolis suburb, had been with Minnesota-based UnitedHealthcare since 2004 and served as CEO for more than three years. He was scheduled to speak at the company’s Investors Day at the Hilton just hours after he was gunned down.

The suspect arrived in the city on a Greyhound bus from Atlanta on the evening of Nov. 24, although it wasn’t immediately clear where the gunman boarded the bus. NYPD detectives are working with Greyhound workers to help identify all passengers, police sources said.

Once in the city, the gunman found his way to the HI New York City Hostel on Amsterdam Ave. near W. 104th St., where cops recovered images of the suspect without a mask and smiling at someone behind the reception desk.

Cops released the images Thursday on the second day of the manhunt.

Aside from that one slip-up, the gunman never revealed his face, including while noshing at a Starbucks or while staying in the room in the hostel he shared with two strangers, Kenny said.

“He didn’t know the two roommates and the entire time he was there he kept his mask on,” Kenny told reporters, adding the suspect did not speak with his roommates, either.

The suspect booked a room at the hostel using a fake New Jersey ID, police said. He also paid cash for everything and didn’t leave a credit card trail.

Investigators have tested a discarded water bottle and protein bar wrapper in a hunt for his DNA. They also were trying to obtain additional information from a cellphone found along the gunman’s escape route.

Anyone with information regarding the suspect’s whereabouts is urged to call NYPD Crime Stoppers at (800) 577-TIPS. All calls will be kept confidential.

With News Wire Services

Originally Published: December 7, 2024 at 9:44 AM EST