Sexual Murder

Can we predict who'll kill again?

Posted May 03, 2012

I read a disturbing article yesterday in a New Delhi newspaper about the murder of three young girls within five days. All three girls were partially disrobed upon discovery and had been raped and strangled. The similarities between the ages of the victims, the manner of death, and the crime scenes have police officers worried they may have a serial killer on their hands and if s/he will kill again.

But how do they know? Can we predict whether or not a person will kill again? Not for sure, but we’re getting closer as more research sheds light on how a sexually motivated serial killer ticks before s/he kills again. 

Sexual Sadism:  Not a Good Sign

According to the ICD-10, sexual sadism is “a preference for sexual activity which involves the infliction of pain or humiliation, or bondage. In order to be diagnosed as a sexual sadist in the United States, you must meet two criteria: “(a) Over a period of at least 6 months, recurrent, intense sexually arousing fantasies, sexual urges, or behaviors involving acts (real, not simulated) in which the psychological or physical suffering (including humiliation) of the victim is sexually exciting to the person; (b) The person must have acted on these sexual urges with a non-consenting person, or the sexual urges or fantasies cause marked distress or interpersonal difficulty.”

Given these rather disturbing criteria, it’s perhaps not surprising that sexual sadism has been linked to recidivism. For example, a 2010 study followed close to 600 male sex offenders for an average of ten years in an attempt to tease out what, if any, characteristics were linked to recidivism. What they found was that sexually sadistic sex offenders, who made up less than 10 percent of the population they studied, were significantly more likely to reoffend in sexual, violent, and general criminal ways.

It’s What You Do, Not What You Have

What they found were that sexually sadistic sex offenders were different from their nonsadistic peers in a number of ways. First of all, they chose different victims; sexual sadists tended to choose adult female strangers while nonsadistic sex offenders were more likely to choose a related child victim.

In terms of repeat offending, it was the specifics of the person’s offenses that were the best predictors of future harm. Sexual sadists most likely to reoffend tended to have more violent first offenses, to demonstrate penile arousal to deviant (violent) sexual stimuli, and engage in tactics designed to humiliate and terrorize the victim. A 2011 study also found that confining the victim, beating or stabbing the victim during the sexual assault, and using threats to evoke fear were prognostic indicators.

Cause for Concern

Obviously, we don’t know much about the New Delhi murders. It may be that the three homicides turn out to be unrelated. But what we do know—the level of violence used, the fact that the victims were strangers—is enough to raise the alert that a serial killer may be at work. And, if I lived in New Delhi, I’d be afraid. Very afraid.