And considering those personality deficits, what in the offender's personality functioning can contribute to commit an isolated sexually abusive act against a child?  or to epetitively sexually abuse a child?

To answer these questions, a clinician looks not only for major mental illness such as schizophrenia but also for depression, because depression, especially a long-standing characterological depression, can set the stage for the kinds of turning to a child to soothe oneself, to provide some basic touching, closeness, intimacy.

A clinician look also at the quantity and, more importantly, the quality of a person's interpersonal relationships.  If a person has a lifelong history of social isolation, of poor relationships, of a general difficulty in establishing intimacy with friends, both cross-sex friends and same-sex friends, that kind of person--because of the need for closeness--is much more prone to turn to a child.  A child, after all, is much easier to approach, is much more receptive, much less judgmental.  So a person who is socially isolated or who has few or poor-quality friendships would certainly be more prone to turn to them.

How does this person manages sexual and aggressive impulses?  If somebody is flooded with sexual impulses or aggressive impulses, some of these impulses might spread to or be inappropriately expressed on the child.

So a clinician looks for signs of sexual or aggressive preoccupation.  That's where projective personality tests fit in, where the personality profiling fits in, and where penile plethysmography fits in.

A clinician looks at sexual development, early sexual history, because early experiences might have predisposed one to look to children--because if one is a victim, one may, at that point, establish a distorted view of relationships between adults and children that may include sexual contact.

A clinician looks also at early development and early signs of difficulty, because with most repetitive child molesters, there are disturbances in emotional personality development that go back to childhood.

A clinician looks for neglect.

A clinician looks for unstable, emotionally-isolating kinds of family experiences that might lead a child to grow up with a sense of hunger that might be expressed inappropriately towards children.

A clinician looks at stress as being a factor that can lead to sudden precipitous losses of control.  Severe alcohol abuse, substance abuse, signs of significant stress -- they can all be factors that can lead to temporary losses of control that might account, for example, for an isolated act of sexual abuse.

See Profiles.