The cameras caught the gunman standing alone for five minutes on West 54th Street, ignoring the early-morning rush of people streaming by.

They caught him again as he stood in the dark at 6:44 a.m. and locked into his target, Brian Thompson, the chief executive of UnitedHealthcare, who was walking on the other side of the street.

Dozens of chief security officers from Fortune 500 corporations around the world joined a video call on Wednesday afternoon, hours after the fatal shooting of the UnitedHealthcare C.E.O. Brian Thompson in Midtown Manhattan, to discuss additional protective measures for executives moving around the area, according to a security expert who participated in the conversation.

The gunman remains on the loose. The NYPD released footage of the hooded suspect at a nearby Starbucks before the shooting. And police officials, who spoke on condition of anonymity, said he may have dropped some vital clues while fleeing.

The suspect in the murder of UnitedHealthcare CEO Brian Thompson was wearing a luxury backpack for photographers that has sparked wild theories on social media.

'They're made for photographers but I guess the side door access works well for hitmen as well,' one person posted, referring to the design.

The bag is named the Everyday Backpack and made by Peak Design and comes with built in compartments to keep photography gear separate.

After users pointed out that the shooter was using the expensive backpack, some speculated that the killer could also be a photographer.

One person said: 'The assassin was wearing a peak design backpack, I wonder what camera he shoots with.'

Another posted: 'The shooter is carrying a very expensive backpack meant to hold camera equipment and opens on each side, made by Peak Design...interesting.'

One other added: 'Peak Design backpack. Probably likes cameras...hobbyist photography and/or travel. Low volume product so easy to identify.'

'It looks like the backpack he is wearing is a Peak Design photographers backpack. That backpack is $300+ and it's very specific for carrying camera gear', another said.

'He is either into photography or he is trying to look like he is a photographer', they added.

Sources told CNN that the man bought two powers bars and a bottle of water from the coffee chain.

Authorities found a phone and a water bottle near the scene that they believe is the one he bought from Starbucks, and could offer them DNA.

The phone could also provide fingerprints and, if technicians can unlock it, could give them an insight into his identity.

Officers also searched Thompson's hotel room, are interviewing his UnitedHealthcare colleagues and reviewing his social media.

They have yet to establish a motive in the killing but sources told ABC 7 they are investigating a possible grudge against the insurance company.

Tisch added: 'Many people passed the suspect, but he appeared to wait for his intended target', and said that it did not 'appear to be a random act of violence'.

'From watching the video, it does seem that he's proficient in the use of firearms as he was able to clear the malfunctions pretty quickly,' NYPD Chief of Detectives Joseph Kenny said

A motive is unclear, and police haven't announced one. But a source with knowledge of the investigation told CNN that UnitedHealthcare's parent company, UnitedHealth Group, was aware of concerning threats against its high-level executives.

The discussion included best practices and reviews of executive protection programs, according to the expert, Dave Komendat, a retired chief security officer at Boeing and president of DSKomendat Risk Management Services, a consultancy based in the Seattle area. He said that all of the security officers on the video call were facing upper-echelon requests for presentations on the current state of their security programs and scrutinizing their own practices.

The man wanted for fatally shooting UnitedHealthcare CEO Brian Thompson in Midtown Wednesday morning was spotted inside a nearby Starbucks before killing his target, police said.

Thompson was named UnitedHealthcare CEO in 2021 and earned a reported $10million a year, and for several years prior, he ran the Medicare business within UnitedHealthcare. He was slated to speak at an investor meeting at the Hilton Hotel soon after the shooting. According to a release from United Healthcare on Tuesday, he would announce the company's hugely profitable 2025 financial outlook, including expected revenues upwards of $450billion.

United is the biggest health insurer by market share in America. The company has been the subject of frequent protests by activists for allegedly systematically denying care for patients. One such protest earlier this year led to the arrests of 11 people outside the United Healthcare headquarters in Minnetonka.

The company made headlines in February after it was subjected to a cyber-attack which cost $872 million.

Thompson is survived by his wife Paulette 'Pauley' Thompson, 51, and their two children who live in the family's $1.5million home in Maple Grove, Minnesota. Mom-of-two Pauley is a practicing physical therapist for Park Nicollet Health Services with over 20 years of experience.

Staff at the Hilton Hotel remained tight-lipped after the shooting, and refused to speak with journalists about that morning's horror. Officials said hours after the shooting that they have made no arrests and the investigation is ongoing.

The NYPD released a new photo of the hooded suspect standing in front of the counter at the Starbucks at W. 56th Street and 6th Avenue, just minutes away from the Hilton hotel where he gunned down Thompson, 50.

Thompson, head of the largest private insurer in the United States, was in New York to speak at an investor conference later on Wednesday