Council on Sex Offender Treatment Treatment of Sex Offenders - Undetected Rapists

Undetected Rapists Behaviors (Lisak, 2002)

The Lisak study observed several particular characteristics used by undetected rapists.

  • These individuals used alcohol deliberately to render victims more vulnerable to attack, or completely unconscious;
  • These individuals were extremely adept at identifying “likely” victims, and testing prospective victims’ boundaries;
  • These individuals planned and premeditated their attacks, using sophisticated strategies to groom their victims for attack, an to isolate them physically;
  • These individuals used “instrumental” not gratuitous violence; they exhibit strong impulse control and use only as much violence as is needed to terrify and coerce their victims into submission;
  • These individuals used psychological weapons-power, control, manipulation, and threats-backed up by physical force, and almost never resort to weapons such as knives or guns; and
  • The majority of undetected rapists are serial rapists who commit other forms of serious interpersonal violence.

Sex offender behaviors are extremely resistant to change, so sanctions to both control and punish deviant behaviors are necessary in protecting public safety. In order to manage their behavior, sex offenders must have external controls (i.e. supervision, support system, law enforcement, registration, child safety zones, electronic or global positioning satellite monitoring, and community notification) and develop internal controls (i.e. identifying triggers and deviant thoughts that precede their offending so it does not lead to the act). Without external restraints many offenders will not follow through with treatment. Internal motivation improves prognosis, but it does not guarantee success.

Last updated April 5, 2010