 Sex workers (particularly those engaging in street prostitution) are also sometimes targeted by serial killers, who may consider them easy targets and less likely to be missed, or who use the religious and social stigma associated with sex workers as justification for their murder.The unidentified serial killer known as Jack the Ripper killed at least five sex workers in London in 1888.Due to the frequent murders of prostitutes at that time and place, however, it is difficult to be certain of the number killed by Jack the Ripper.