LISA DESJARDINS: Good evening.

I'm Lisa# Desjardins.

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

ERIKA KIRK, Widow of Charlie Kirk: 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.

LISA DESJARDINS: Concerns about security for# political figures and of political violence## in general continue to rise.

Cynthia# Miller-Idriss 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?

CYNTHIA MILLER-IDRISS, American University: 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 weren't able# to tamp down the rhetoric.

LISA DESJARDINS: 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.

And 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.

How much does political rhetoric influence# someone to move from saying words to doing## something violent?

Or does it?

CYNTHIA MILLER-IDRISS: Yeah, I mean,## one of the things we'd seen, and I# said this a year ago after Trump,## the first assassination attempt against President# Trump, was that it was only a matter of time## with the kind of rhetoric that we see, that# were going get to political assassination.

So, you know, that's what I mean by# expected.

It sounds very cynical,## but it was very predictable.

You know, shocking# but not surprising is the way that I think of it.

When you have political rhetoric that# consistently positions us versus them## in existential terms, when people online# are celebrating the assassination of a## United Healthcare executive, for example,# that kind of violence being valorized,## not just seen as a last type of solution,# but as an acceptable or even preferable one.

LISA DESJARDINS: There was# also celebration online of## this assassination.

And at the same time,# we also know there are some supporters of## Charlie Crook who are using more and# more sort of warlike kind of talk.

After a tragedy like this, there are# all sorts of ways that people deal## with the grief.

But where do you think we are# right now in the rhetoric about this event?

CYNTHIA MILLER-IDRISS: I think we're# at a really very risky moment.

I will## say that the elected officials rhetoric, the# bipartisan and mostly bipartisan condemnation## of the violence and of, you know, the# idea that no one deserves to be shot,## no matter how much you disagree with# them, I think has been very clear.

But among ordinary people, especially# young people on social media,## we have seen much more divisive rhetoric,# both calling for civil war and celebrating## the death of the killing of someone with# whom people often vehemently disagreed.

And so I think one of the things I've# been urging people is to not just look## to political leaders for solutions, but# look across the dinner table.

That's## a moment to engage with dialogue and# really try to walk back that rhetoric.

LISA DESJARDINS: One thing I've noticed in# the past few days is a rise in conservatives## doxing or publishing the personal information of# people -- individuals who are not remotely famous,## who may have in some cases celebrated# the death of Charlie Kirk.

As you said,## that's something obviously deplorable to do.

But some -- in some cases, maybe not gone# that far, just offended some folks.

We spoke## to someone from Wired magazine who's covering# this, talking about specifically this moment.

DAVID GILBERT, Wired: I've spoken to multiple# people this week who have had, you know,## their employment terminated as a result# of what they posted online.

In some cases,## they were celebrating Charlie Kirk's# death.

In other cases, it was much,## much less than that.

And they were just# making points about device of your society.

LISA DESJARDINS: This has been# not just about shaming people,## but about affecting their lives.

And in some# case, we know there's been death threats as## well.

I wonder what you make of this tactic.# Not just something a few people are doing,## but people are collecting# databases to do this now.

CYNTHIA MILLER-IDRISS: Yeah, doxing is a very# dangerous tactic from.

We've seen it from the## left and from the right.

And what we've seen# over the years is that often when someone is## doxxed their personal information, leaked, there# have been cases where people show up at the wrong## address where they used to live, let's say, and# threaten a kind of innocent family who lives## there.

You're putting at risk family members,# children, others who might live at that address.

So, you know, one of the things I would really# urge people to do is avoid that temptation,## whatever the motivation to look for# accountability.

This is a moment to## allow the rule of law, to allow social# media policies to allow to handle that.

LISA DESJARDINS: In the few seconds we have left# here.

We've seen these moments in history before## where we have assassination attempts happening# over a decade or two decades kind of thing before.

But I wonder, you mentioned people need to# talk to each other across the dinner table.## What else gets the country# out of moments like this?

CYNTHIA MILLER-IDRISS: Well, one of the# things we really need is more serious and## systematic investments in prevention, which# is something that other countries have.

We in## this country tend to rely on after the fact# increases in security, better barricades,## better security detectors.

And that's expensive# and it requires a perfection every time.

But you can also invest in helping people# be less persuaded by propaganda online,## less persuaded by manipulative efforts# that say violence is the solution and## help people know how to recognize warning# signs and know where to get more help.

LISA DESJARDINS: Cynthia Miller-Idriss,# thank you so much for joining us.

CYNTHIA MILLER-IDRISS: Thanks for having me.