Can you predict killing sprees? What do mass killers have in common? Why do so many of them write manifestos online and what do these tell us? These are some of the questions David J. Krajicek seeks to answer in Mass Killings, on a topic that is becoming increasing urgent and desperate. In recent decades, mass shootings worldwide have increased in their savagery and frequency. Nearly all mass killers are male - and many of them are bound together by misogyny, misanthropy, and racism. They do not just "snap." They plan their assaults for months or years, drawing up detailed battle plans, and accumulating weaponry. They document the process in journals or videos online, understanding that they are leaving evidence which will help the marquee lights of their futile crimes burn brighter and longer. Krajicek shows the commonalities between mass shooters, and describes the psychopathic process that leads these troubled men to commit atrocities. Mass killers feed off each other's words and deeds, and it's crucial to be able to read the signals they give out to prevent future tragedies.