UnitedHealthcare CEO assassination: Crime expert breaks down questions investigators are trying to solve

As the search for UnitedHealthcare CEO Brian Thompson's killer enters a fourth day, detectives across the country are working overtime to gather information that will bring the suspect to justice.

Thompson, who was shot outside a New York City hotel just before 7 a.m. Wednesday, died less than 30 minutes later. Detectives are investigating a number of clues the suspect left behind, including a backpack, a water bottle, a phone and shell casings.

Philip Holloway, an attorney and legal analyst with a background in law enforcement, broke down what New York and federal investigators might be thinking during an interview with Fox News Digital Saturday.

Though national media coverage has been focused on the search for the suspect, who is believed to have left New York, Holloway posited that the gunman may not have acted alone.

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Philip Holloway spoke to Fox News Digital about the search for CEO Brian Thompson's killer. (Peter Gerber/NYPD)

"Obviously, if the killer had any assistance before, during or after the murder, law enforcement would want to build a solid case against any such accomplice," the former police officer explained. "If they are looking at anybody like that, they don’t want to alert them of that fact.

"The bigger question is how does someone know exactly what time he's going to be walking out the door at 6:45 a.m.?"

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Holloway, a frequent Fox News Channel guest, also addressed speculation about whether police have the suspect's name. During a press conference Saturday, New York City Mayor Eric Adams seemed to imply authorities may know the gunman's identity.

"We don’t want to release that now," Adams said. "If we do, we are basically giving a tip to the person we are seeking, and we do not want to give him an upper hand at all.

"Let him continue to believe he can hide behind the mask," the mayor added. "We revealed his face. We’re going to reveal who he is, and we’re going to bring him to justice."

UnitedHealthcare CEO Brian Thompson was shot and killed in midtown Manhattan Wednesday morning. (Businesswire | NYPD Crimestoppers)

Holloway told Fox News Digital the intent was to protect the investigation.

"The only reason to withhold the name of the suspect, assuming the name is known — and I suspect the name is, in fact, known — is to protect some ongoing aspect of the investigation," Holloway said. "And, to that point, the thing that makes the most logical sense is that the authorities are looking at whether or not any other person(s) may be involved."

Though Holloway is not involved in the investigation, he told Fox News Digital he's "about 90% sure" that one or two other suspects were involved in the murder.

But he also emphasized that anything is possible this early in the investigation.

Investigators were seen in Central Park Saturday as the search for Brian Thompson's killer continues. (Peter Gerber)

"When all we have is bits and pieces of the puzzle, the imagination tries to fill in the gaps," Holloway said. "At this point, almost anything is plausible. We will have a clearer picture in the hours and days ahead."

Andrea Margolis is a writer for Fox News Digital and Fox Business. Readers can send story tips to This email address is being protected from spambots. You need JavaScript enabled to view it..