Interesting detail: He was armed with a veterinary pistol, used for euthanizing animals, which looks like the gun he used.

Weird detail: He was caught using a fake ID at a McDonald's. Why would someone have to use an ID at McDonald's?

Not sure if this is our killer.

Actually, now that I re-read the story, I think someone called a tip on the guy, recognizing him from his photo. When the police showed up, he showed a fake ID and gave a false name.

The cops, presumably, used the fake ID as the reason to arrest him while they try to figure out if he's Taylor Lorenz's favorite boy band murderer.

A person of interest was nabbed Monday in the fatal shooting of UnitedHealthcare CEO Brian Thompson -- busted possibly trying to use a fake ID in a McDonald's, law enforcement sources said.

The man -- who sources said is being eyed for the coldblooded, targeted execution in front of a Manhattan hotel last week -- allegedly had a manifesto on him when he was taken into custody by cops in Altoona, Pa.

He also had a gun, silencer, four fake IDs and other items "consistent" with what authorities were looking for in the case, sources said.

Law enforcement was still trying to figure out the man's real identity, sources said.

He was nabbed on a tip called in to local cops, who apprehended him, sources said.

The NYPD was on its way to Altoona late Monday morning, sources said.