Abstract Establishing an empirically valid typology of sexual murder is necessary for developing theory, risk assessment, and intervention. Results from all empirical studies conducted between 1970 and 2016, drawing on information pertaining to > 700 sexual murderers, were collated to provide a definitive best evidence synthesis elucidating the overall patterns and motives underlying sexual murder. Three subtypes of sexual murder were consistently found. The term sexualized murder is proposed, to refer to those crimes in which killing is functionally related to the sexual element of the offence. Grievance murder is driven by angry schema and an excessively aggressive response style. Finally, rape murder involves only an indirect association between the sexual offence and killing. Factors distinguishing these subtypes are discussed, and attention is directed towards gaps in knowledge, particularly in relation to biopsychosocial and criminal career factors that remain under-researched.