Cooling-Off Periods among Serial Killers

Theory and empirical research in criminology have paid less attention to intermittency in offending, that is, the brief lapses and sporadic episodes of crime that occur at sometimes unpredictable intervals (Piquero, 2004). This is mainly due to the problem of defining this phenomenon in a common operational way that can be tested empirically. This has thus led to its abandonment in most contemporary definitions of serial murder (Osborn & Salfati, 2014). Most up-to-date definitions have recognized the fact that serial murders are committed as discrete events (Adjorlolo & Chan, 2014). While psychological, sociological, and geographical theories of serial murder can be used to explain cooling-off periods, none of these theories have, thus far, been used in an empirical study. This article examines the phenomenon of cooling-off periods in relation to serial murder. Although definitions of serial murder have changed over the years, there is a consensus that between every two murders there must be a cooling-off period (Homant & Kennedy, 2014; Morton & McNamara, 2005). Unlike previous research, our study, which is based on the Encyclopedia of Serial Killers (Newton, 2005) found that the longest cooling-off period is between the first and the third murders (i.e., a series). We offer some theoretical psychological explanations for this pattern, although we were unable to study it empirically. We conclude that it is less important how different scholars define cooling-off periods; the important thing is that this phenomenon exists and has meaning for understanding, profiling, and even forecasting the time of the next murder.