Police today said fingerprints and shell casings collected at the scene of last week's murder

of United Health Care CEO Brian Thompson are directly connected to their prime suspect, Luigi

Mangione.

The fingerprints matched the 26-year-olds and the casings matched the gun found on him when

he was arrested earlier this week in Pennsylvania. To break down the latest, I'm joined now by William Brangham in New York.

So, William, we have this new evidence now linking the alleged shooter here to the crime.

Police also say that they're in possession of some notes written by him.

What kind of insight is that giving us?

What have we learned? And especially as it

relates to motive in this case? That's right, Omna. Police have at least two different pieces of

writing from this suspect. One is a notebook that is allegedly full of planning details. And the other

is what people have been calling his manifesto. It's a 260-word handwritten document

where reportedly he takes credit and claims responsibility for this killing. Now, the police have

not released that manifesto in its entirety. One journalist claims to have a copy of it, and he's posted

it on his website, and it is now

floating all over the internet. But what we know from police sources, details of that is that

the suspect describes the killing as a, quote, symbolic takedown and generally expresses his

now well-documented fury and anger at the health care industry in general.

And that is what has been, as we've reported, resonated with so many people who seem willing to look past the grisly murderer and still side with him in their complaints as far as health insurance is run in this country.

The notebook that the police have described some of the planning process reportedly that

he's going to go after an as yet unnamed health care CEO at a meeting, that that would be

a quote, targeted, precise, and it doesn't risk innocence, which apparently the suspect thought about using

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