See also: Crime fiction, Stockholm syndrome
Of course, we'll want more than just a definition--help expand this article!
One particularly well known example of a class at increased risk to varying forms of attacks is the "streetwalker" prostitute. These people have been known anecdotally to have an abnormally high incidence of murder, and for said murders to go unresolved frequently. Victimological studies of the matter might investigate current societal mores (expectations, roles, social status), legal status of prostitutes, typical working/living conditions, statistical analysis of the actual increased risk and secondary risk factors, and the economic activity of streetwalkers.