This book is the product of a windfall encounter. Each of us individually would have probably written a quite different book – or, even more likely, no book at all. We were lucky enough that our paths crossed at a workshop in Freiburg, Germany, in March of 2017. At the time, both of us had, independent of each other, only recently started to engage with predictive policing. The research outlines that both of us presented at that workshop were remarkably similar, and as it turned out during a couple of longer follow-up conversations, we were in fact interested in almost identical questions surrounding the use of algorithmic crime analysis software. There was a large overlap in the theoretical and conceptual literature that we had been reading. And we had at that point even started to interview some of the same police representatives and software developers.