New York police released photos Thursday of a person wanted in connection with the fatal shooting of UnitedHealthcare CEO Brian Thompson in Manhattan, after asking the public for help in finding evidence leading to the killer could lead. The NYPD has said the killing was not random but appeared to target Thompson, who ran a massive health care provider that employed more than 400,000 people and insured millions of members.

We don’t yet know what the motive was for the Midtown Killer, who is now the subject of a manhunt. We know something went terribly wrong when Thompson walked across the street to attend his company’s investor meeting.

With numbers like that, the number of potential suspects is enormous, even if we have a photo of a person of interest.

The discovery of the words “deny, defend, deny” on recovered bullets and shell casings is consistent with possible anger toward the CEO or the company, although this is also inconclusive. A disgruntled employee might be seething over a recent termination, layoff, or poor performance review. Or it could be something else entirely. CEOs often become the personification of their company – for the good, the bad and the ugly. For this reason, it is entirely possible that the shooter never met the CEO, but instead identified Thompson as the person responsible for a perceived injustice in which he played no direct role.

After retiring from the FBI, I became the Director of Corporate Security for a Fortune 10 company and one of the largest in the world. Here’s what stands out to me about Thompson’s murder and what the investigation is likely to entail.

First, the killer knew where Thompson was. The investor meeting was announced publicly. This is helpful to investigators because the shooter was likely lurking outside Thompson’s hotel or the conference hotel, or even monitoring Thompson as he left home to travel to New York. There may be security video, rental car or toll records showing the shooter’s travels to Midtown Manhattan.

Second, shooters like this often reveal their intentions by expressing real or perceived grievances. That means UnitedHealthcare’s security team may already know the killer’s name in its file of threat communications to its CEO. Rest assured that the NYPD is reviewing these communications. There may even be a letter from the killer to the company that shows his fingerprints and perhaps even his return address.

Third, police said in their press conference that they recovered three live bullets at the scene, which was likely due to the shooter trying to remove his jammed weapon. I have sometimes seen fingerprints and even DNA from bullets found at crime scenes. A cell phone was also found nearby, which, if it belonged to the killer, would provide a wealth of information, particularly geolocating his whereabouts leading up to the shooting.

Police also said the shooter left the scene, got an electric bike and went to Central Park. Investigators said they were working to determine what type of e-bike the shooter was riding and whether they were able to determine his current location.

Finally, I’m surprised that, according to police, Thompson wasn’t accompanied by a security detail. Reached by NBC News, Thompson’s wife said her husband had spoken of threats against him. In my experience, high-profile investor meetings and annual shareholder meetings are fraught with security challenges. The SEC requires publicly traded companies to hold annual shareholder meetings, and these are typically open to anyone who owns a single share of the company’s stock. Although this conference was aimed at analysts and institutional investors, it was still a publicly announced target for anyone with malicious intent. Perhaps the shooter knew that Thompson did not employ security personnel and that security would be tighter in the conference itself, for example. Maybe that’s why the shooting took place outside.

This shooter is eventually identified. We know what, where and when this murder happened, but Brian Thompson’s wife and family deserve answers to the nagging question, “Why?” Let’s hope they get that answer. It won’t bring them any comfort, but it could help safety leaders at companies across the country reduce the risk of a similar tragedy happening again.