The nationwide manhunt for the gunman suspected of killing UnitedHealthCare CEO Brian Thompson entered its fifth day Sunday.

Police released the latest photos of the suspect late Saturday evening, apparently showing the man in the back of a taxi. Police also recovered a backpack they believe is linked to the killer, which contained a jacket and Monopoly money but no gun. Police believe the gunman fled New York City on a bus shortly after the shooting.

A New York Police Department dive team also searched a pond in Central Park on Saturday, near where the backpack was found.

The divers were seen behind an area cordoned off with police tape next to the Bethesda Fountain in a body of water known as a lake near the park’s boathouse.

SHOCKING VIDEO SHOWS UNITEDHEALTHCARE CEO BRIAN THOMPSON BEING SHOT ON THE STREET OF NYC

The NYPD was Search Central Park since Wednesday.

The NYPD initially announced that it was offering $10,000 for information leading to the arrest and conviction of the suspect. The FBI announced late Friday that it had offered up to $50,000 for information leading to the arrest and conviction of the suspect.

On the day of the shooting, investigators already knew that the bomber fled through Central Park and arrived about four minutes after Thompson was shot. At 6:56 a.m. he left the park again at 77th Street on the Upper West Side, according to a detailed schedule announced by Detective Chief Joseph Kenny at a news conference Friday.

A map shows the known locations of UnitedHealthcare CEO Brian Thompson’s suspected killer. (Fox News)

Two minutes later he was spotted again on 86th Street, still on his bike. At 7:04 a.m. he was seen walking and then getting into a taxi.

FORMER NYPD INSPECTOR “SKEPTIC” UNITEDHEALTHCARE CEO GUNMAN WAS PROFESSIONAL, DESIGNED ON THE WEAPON OF YOUR CHOICE

Police believe he is no longer in New York City because footage showed the taxi dropping him off at the Port Authority bus station, but investigators were unable to find any footage of him leaving again. The station serves routes that could have taken it to New Jersey, north toward Boston, or south toward Philadelphia and Washington, DC

A Peak Designs backpack that the NYPD last found in a pile of leaves in Central Park on Friday, December 6, 2020. The bag appears to match the description of the bag carried by the gunman who killed United Healthcare CEO Brian Thompson on Wednesday morning. (Received from New York Post)

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Retired FBI agent Scott Duffey told Fox News Digital that the backpack will be taken to a lab in Queens for forensic examination, where it will undergo trace processing.

“(It’s) a process for hair, fibers (and) DNA,” Duffey explained Saturday. “If he puts his hand against the strap and tightens the buckle, as most of us do, there is likely to be DNA there. And zippers.”

Fox News’ Landon Mion and Christina Coulter contributed to this report