CNN
MILWAUKEE (CBS 58) -- Charlie Kirk’s murder is the latest of several high profile acts or threats of political violence.
Some of them have happened right here in Wisconsin.
One of the country's foremost experts on political violence said as tragic as it is, Kirk's assassination was not unexpected based on a years-long spike in incidents. And he cautions it could continue.
Dr. Robert Pape is a professor of political science at the University of Chicago. He told us, "This is the era of violent populism."
Pape says political violence has become a shockingly regular feature of American political life.
The number of incidents his research team tracks has jumped five times every single year since 2017.
Pape said, "You would have to go back to the 1960s to find a surge of political