Some killers might be categorized as a specific type of multicidal offender but might actually fit two (or more) classifications. We’re concerned in this chapter only with those who have participated in a spree (at least three deaths, two locations) as a component of their crimes. They might be serial killers who go on a spree, or they might be mass murderers who took victims just before or soon after the primary carnage. The spree places them into this book, but the mix of other types of multicide creates a distinct subcategory. There might be utility for law enforcement if there are clear targets or a mission that becomes known before it is finished. For example, a spree/mass murderer like Brenton Tarrant, described in Chapter 3, became visible at once through his posted manifesto, live-streamed video, and signature targets. Calls to police and their awareness of his mission got him pulled over before he could reach a third location. A spree that might have ended many more lives was terminated in just over half an hour.