The subject of sex offenses committed by women has not received very much attention until now. In the light of the much more significant numbers of offenses committed by men, female sexual criminality has always taken a back seat and is frequently overlooked altogether. The very idea of its existence came up against a lot of resistance for many years; it just seemed too absurd that a woman could be sexually dangerous for a child or a man. The fact that female sex crime has been shrouded in silence for so long has concealed its grave consequences and implications, and yet the survivors of female sexual abuse have reported that sexual abuse by women was more harmful and detrimental than any sexual abuse they had experienced from men.

From a total 4,712 publications, identified using keywords searches on Medline, EMBASE, and PsycInfo (1984 to December 2011), we selected 61 papers using methodological criteria of evidence-based medicine. Our literature review studied 6,293 cases of female sex offenders in these 611 publications.

Our review, conducted on a large population covering 61 of the most recent acceptable evidence-based studies, enables us to confirm three already-known suppositions: (1) female sex offenders have themselves often been victims not only of sex abuse (49.1%), but perhaps more importantly, of other types of family violence and instability (55.4%); (2) 51.2% suffer from psychiatric disorders, depression and/or mental retardation; (3) they are more likely to attack their own children or other close relatives before looking for victims outside of their family unit (63.9%). However, there are other generally held beliefs that do not seem to be based on fact and should certainly be reviewed, in particular concerning the belief that female sex offenders are not dangerous: 1) alcohol and drug abuse appeared in our series as less significant (29.1%) than previously described in older research, and seemed to confirm the results found with more rigourous data and larger scope studies described in the more recent literature; 2) female sex offenders are more likely to choose male victims (60%) over female victims (40%); 13.3% of them do not have any sexual preference; 3) contrary to popular belief, more female sex offenders commit their first crime alone than with an accomplice (66.7% of them act alone); 4) violence and coercion is far from absent when a female commits a sex offense (45.8% of cases); 5) although repeat sex offenses are rare, in a large number of cases (40.3%), female sex offenders have already been charged with other criminal offenses, or have repeat offenses in non-sexual criminal acts.