Good evening. I'm Lisa Desjardin. John Yang is away. The assassination of American conservative leader Charlie Kirk is drawing reaction and concern around the world. In London, a massive crowd today, estimated at over 100,000 people gathered in a march organized by anti-immigration activists who remembered Kirk as part of the event.

This as the 22-year-old suspect in the killing is being held without bond due to appear in

court Tuesday. As the investigation into the shooter's motives goes on, Kirk's widow, Erica,

spoke for the first time last night, vowing that his movement will not only continue, but will grow.

You have no idea the fire that you have ignited within this wife?

The cries of this widow will echo around the world like a battle cry.

Concerns about security for political figures and of political violence in general continue to rise.

Cynthia Miller Idris is the director of the polarization and extremism research innovation lab at American University,

and she joins me now.

Cynthia, looking at the pattern of violence in recent years, what fits into that pattern from

this and what might be new?

Well, we've been seeing rising political violence, rising hate-fueled violence for several

years now.

We're at a level that we haven't seen since the 1970s.

And over the last couple of years, in the U.S. in particular, we've seen rising assassination

attempts and assassinations as a tactic within that political extremism.

And that's also been happening overseas.

So, you know, I think it's, it was to be expected that political assassinations would continue if we weren't able to tamp down the rhetoric.

To be expected to hear those words is really quite stunning.

But you are the one doing the research and you're talking about the rhetoric, which is a big part of the conversation right now.

How much is rhetoric responsible for political violence? And especially that moment where

someone isn't just expressing anger, as we see online everywhere, kind of a toxic culture online,

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