Tuesday's school shooting in Portland, Oregon marks the 74th school shooting in less than two years.

It's yet another example of the prevalence of violence in and around school campuses following other shooting incidents over the past couple of weeks in Seattle, Washington at Seattle Pacific University and Isla Vista, California near UC Santa Barbara.

Dr. Katherine Newman is the dean of the Krieger School of Arts and Sciences at Johns Hopkins University and co-author of the book "Rampage: The Social Roots of School Shootings."

She joins Take Two to talk about the tragic trend of school shootings at the K-12 and college level and what these tragedies have in common.