Suspect in UnitedHealthcare’s CEO killing has eluded police for nearly a week

(CNN) — He’s out there – somewhere. Nearly a week after a gunman fatally shot a health care executive on a busy New York City street, authorities know what the suspect looks like but they don’t know who or where he is. Through glimpses of his unmasked face, his movements through the country’s largest city and the belongings police say he discarded, he seems almost familiar but remains a mystery.

The public, too, has seen the suspect in surveillance photos and videos – including one with him pointing the weapon at UnitedHealthcare CEO Brian Thompson’s back – and as he continues to evade capture in the December 4 killing outside a Midtown Manhattan hotel.

The suspect is believed to have left New York City on an interstate bus, police officials said, after video cameras captured him entering the George Washington Bridge Bus Station on 178th Street but not leaving.

Then, over the weekend:

• Police released new photos of the suspect: in the backseat of a taxi and wearing a jacket while walking on the street. In both, he’s wearing a hood and a face mask.
• A backpack believed to be the suspect’s was recovered Friday in Central Park, a law enforcement source said. It contained money from the Monopoly board game, a law enforcement source told CNN. It also contained a Tommy Hilfiger jacket, law enforcement officials briefed on the matter said.
• Police divers did not find the weapon used in the shooting in their search Sunday of a lake in Central Park, a law enforcement official told CNN, after searching the park’s iconic boathouse and Bethesda Fountain a day prior. Also still missing is an electric bike the suspect rode toward Central Park, according to surveillance images released by authorities.

Given the suspect’s missteps so far – and mistakes he could make during the manhunt – learning his identity will likely help determine patterns that lead to his eventual capture, experts told CNN. With mounting clues and likely hundreds of authorities searching for him, how much longer can he avoid getting caught?

‘You’re bound to make mistakes’

A determination of the suspect’s identity should come soon, former FBI profiler Mary Ellen O’Toole said.

“I’m thinking we’re going to know who this is within a matter of a few more days, if that,” O’Toole told CNN. “He’s completely outnumbered. With that kind of manpower behind their efforts, they’re going to come up with the information that identifies him.”

The suspect made missteps before and after the attack that could lead authorities closer to finding him, experts say.

“The ability to stand up against that kind of an investigation, one person can’t do it, no matter how arrogant you are,” she said. “You’re bound to make mistakes.”

Some of the suspect’s actions – such as pulling his mask down on camera and leaving behind inscribed shell casings, a burner phone and a partial fingerprint on a water bottle – have only added to the clues left behind for authorities.

Police have also traced his movements before the shooting via a Greyhound bus originating in Atlanta and bound for New York City.

“The thing that works against the shooter is that law enforcement will get better, but the shooter can’t go back and undo what he’s already done,” O’Toole said.

The shooter appears to have perhaps only practiced such a killing before, rather than being an experienced assassin, O’Toole said. Leaving shell casings or Monopoly money behind for authorities would not typically align with the actions of a killer who wanted “to blend back into oblivion,” she said.

Minimizing the number of actions a fugitive takes before and after a crime is crucial to avoid getting caught, said Peter Young, a former FBI fugitive who evaded capture for more than seven years on terrorism charges related to releases of animals from fur farms.

“It sounds like this person did not adhere to that,” Young told CNN. “If he was stopping at Starbucks, that sounds like an unnecessary risk.”

Under pressure and running out of options

After several days of evading capture by the FBI, New York Police Department and other agencies, the psychological pressure of being on the run and the focus of a widespread search could lead to errors, O’Toole said.

“It would be absolutely overwhelming and there’s nothing that he can do about it, and this is where he will make mistakes,” she said. “In the shoes of the shooter right now, he is dealing with emotions and consequences that I don’t think he anticipated at all.”

It’s possible the suspect could lose the critical thinking skills needed to strategically evade capture under the mounting pressure, the expert said.

“His options are getting fewer and fewer and fewer, and then on top of that, his ability to make good decisions is deteriorating,” O’Toole said.

“(With) the reality that he can never go back to a normal life the way it was before last week, all of those can result in very poor decision-making,” she added.

How the suspect’s identity will help investigators find him

As investigators zero in on the suspect and his identity, they will be able to examine details about his life that could be crucial to the case, O’Toole said.

“They’ll be looking for his patterns of behavior,” she said. “You start looking at, ‘Where does he work? Where does he go after work? Does he work out in the gym? Does he walk his family dog?’

“It’s really difficult for us to break every pattern of behavior that we depend on in our lives, so eventually you default to going into Starbucks to get your coffee, or you default to getting up at 6 o’clock in the morning and going for a run,” she added.

The morning before the shooting, the suspect was spotted ordering a bottle of water and two energy bars from Starbucks, images released by authorities show.

New photos released early Sunday by the FBI and the NYPD show the hooded suspect wearing dark clothing while sitting in the back of a taxi, his face partially covered in a blue mask as his eyes appear to stare directly into the cab’s camera.

Similar photos show him outside the taxi, appearing to walk down the street.

Authorities also hope someone who knows the suspect will come forward. The FBI is offering up to $50,000 of reward money for information leading to his arrest and conviction. The NYPD has added another $10,000.

Search for key evidence continues

Meanwhile, the gun police believe was used in the shooting remains missing.

After inspecting a backpack police sources said may have belonged to the shooter, authorities determined no gun was inside. That prompted a search by divers in Central Park over the weekend. It came up empty.

The backpack contained a Tommy Hilfiger jacket and Monopoly money, a law enforcement source told CNN.

Police have also found a burner phone they believe the suspect used and a water bottle they believe he touched. So far, a fingerprint recovered from the phone and DNA from the bottle – and an energy bar wrapper the suspect is said to have bought – have not yielded matches when compared against law enforcement databases, according to a law enforcement official.

Investigators have also recovered 9 mm shell casings from the scene of the shooting with the words “delay,” “deny” and “depose” written on them, according to Joseph Kenny, the chief detective of the NYPD.

Police are looking into whether the words, similar in phrasing to a common description of insurance company tactics – “Delay, deny, defend” – may point to a motive. A 2010 book critiquing the insurance industry is titled, “Delay Deny Defend.”