The suspected UnitedHealthcare CEO killer planned his attack well – but made crucial mistakes, experts say

Here's a look at what police investigating the shooting of a U.S. health insurance CEO say are the suspect's key moves, the evidence he left behind, and what experts say about his strategy:

At first glance, the assassin seemed too meticulous to be an amateur and too careless to be a professional.

But the man suspected of killing UnitedHealthcare CEO Brian Thompson on a New York City sidewalk managed to evade capture for days – puzzling even law enforcement experts.

“What surprises me is how well planned the actual attack was, and at the same time how sloppy the killer was in his movements – in his showing his face, in leaving behind items,” said Steve Moore, a retired FBI supervisory special agent.

“There’s kind of a dichotomy. It’s almost as if he read a book on how to do one of these attacks and didn’t read it carefully. He just made serious mistakes as he went along.”

The suspect’s evasion ended Monday at a McDonald’s in Pennsylvania – where police arrested Luigi Mangione in connection with the killing.

Here’s a look at what police say are the suspect’s key moves, the evidence he left behind, and what experts say about his strategy:

He took a bus to New York and paid cash: The suspect cleverly avoided air travel – and the intense scrutiny that comes with it, experts said.