UnitedHealthcare CEO Brian Thompson's Wife Claims He Had Received Threats

The wife of slain UnitedHealthcare CEO Brian Thompson says he had received threats before his shocking assassination on the streets of NYC.

In a phone conversation with NBC News read out by the anchor ... Paulette Thompson said, "There had been some threats basically. I don't know. A lack of coverage? I don't know details. I just know that he said there were some people that had been threatening him."

Law enforcement sources tell TMZ there’s no official record of any threats being reported by Brian or any other UnitedHealthcare executives.

Chillingly, 12 hours after Thompson's early-morning murder Wednesday, someone made a bomb threat targeting his Minnesota house, docs obtained by TMZ reveal. A bomb squad was dispatched -- but they didn't find any explosive device.

The bomb squad also went to Paulette's house a few blocks away. Brian and Paulette have been separated for years, but lived close to each other -- one of their 2 children is still a minor.

For the time being, sources tell us that Minnetonka Police have been stationed at UnitedHealthcare’s headquarters in Minnesota, ramping up patrols around the company’s other offices in the area. They’re also in close contact with UnitedHealthcare Security.

As we know, the masked gunman who took out Thompson didn’t just pull the trigger -- he left a chilling message behind. The bullets he used had the words "deny," "depose, and "defend" carved into the shell casings.

Two of the words -- "deny" and "defend" -- also appear in the title of a 2010 book, "Delay, Deny, Defend," written about the health insurance industry. And, of course, Thompson was one of the big players in that very sector.

Our sources are saying the suspect -- or possibly someone close to him -- might’ve been denied coverage by Thompson’s company for a medical procedure -- and that could explain the targeted hit. As of now, though, the killer is still on the run.