barry latzer has written a new book the rise and fall of violent crime in america. what inspired you to reinvestigate the issue of the violent crime? >> guest: no one had studied in a comprehensive way the history of violent crime. i felt that needed to be done especially because as we both know, the violent crime rate had sky rocketed in the 60s and had really become a major concern for the entire nation for the next several decades, two and a half decades. i felt given the significant violent crime in the postwar period, the major work on that needed to be done. >> host: you do something really unique in this book. when people talk about violent crime they talk about the 60s and 70s. what made you decide that he wanted to take a perspective on the violent crime? >> guest: when i wrote the manuscript i went back even further than that, but they decided to publish the period from the 1940s and on, the period of the memory of people that are still alive. and i feel that is to really understand violent crime and most major phenomenon. one has to go back in time and se