Police release new photos in the search for the gunman in the United Healthcare CEO killing

NEW YORK - The masked gunman who stalked and killed the leader of one of the largest U.S. health insurance companies outside a Manhattan hotel used ammunition emblazoned with the words "deny," "defend" and "depose," two law enforcement officials said Thursday.

The words were written in permanent marker, according to one of the officials, who were not authorized to publicly discuss details of the ongoing investigation and spoke to The Associated Press on the condition of anonymity.

Police also released photos of a person they said was wanted for questioning in connection with the shooting.

United Healthcare CEO Brian Thompson, 50, died in a dawn ambush Wednesday as he walked to the company's annual investor conference at a Hilton hotel in Midtown, blocks from tourist draws like Radio City Music Hall and the Museum of Modern Art.

The reason behind the killing remained unknown, but investigators believe it was a targeted attack.

The message left on the ammunition echoes the phrase "delay, deny, defend," which is commonly used by attorneys and insurance industry critics to describe tactics used to avoid paying claims. It refers to insurers delaying payment, denying a claim and then defending their actions.

Health insurers like UnitedHealthcare have become frequent targets of criticism from doctors and patients for complicating access to care.

Investigators recovered several 9 mm shell casings from outside the hotel and a cellphone from the alleyway through which the shooter fled.

The killing and the shooter's movements in the minutes before and afterward were captured on some of the multitudes of security cameras present in that part of the city.

The hunt for the shooter brought New York City police Thursday morning to at least two hostels on Manhattan's Upper West Side, based on a tip that the suspected shooter may have stayed at one of the residences, according to one of the law enforcement officials briefed on the investigation.

The photos police released Thursday of a man wanted for questioning appeared to have been taken in the lobby of the HI New York City hostel, according to images of the lobby available online. The man is smiling in one of the photos.

"We are fully cooperating with the NYPD and, as this is an active investigation, can not comment at this time," Danielle Brumfitt, a spokesperson for the hostel said in an emailed statement.

Investigators believe, judging from surveillance video and evidence collected from the scene, that the shooter had at least some prior firearms training and experience with guns and the weapon was equipped with a silencer, said one of the law enforcement officials who spoke with the AP.

Investigators also were looking into whether the suspect had pre-positioned a bike as part of an escape plan, the official said. The shooter fled on a bike and was last seen riding into Central Park.