Few studies have compared single and serial homicide offenders' criminal histories. To understand more completely how these offenders differ, Multidimensional Scalogram Analysis (MSA) is used to compare single and serial homicide offenders' profiles comprised of 10 prior offending variables. The profiles of offenders overall co-occurred in four thematic groupings that were differentiated by the type of violent offenses contained in that group and whether the offenses were aimed at people, property, or both. Results additionally showed that most serial offenders had criminal history profiles that were unique from one another and from single offenders. The implications for differentiating offenders are discussed. Figures and references (Published Abstract)