A Case of Abrupt Onset Sexual Predatory Behavior with Minors

TASA ID: 1650

In legal cases involving the apparent abrupt onset of illegal sexual behavior with minors, prosecutors and defense attorneys should be alert to the possibility of behavior-variant frontotemporal dementia (bvFTLD) as a causation factor in young adults where there is no prior history. While the signs and symptoms of this brain dysfunction are generally seen in individuals age 50 and older, they can occasionally appear as early as age 20. The relevant signs of bvFLTD are disinhibition, impulsiveness, poor judgment, loss of empathy/sympathy and compulsive sexually inappropriate behavior. Not all signs may be exhibited in all individuals and other signs and symptoms can be present in variations of the disorder. The cause is unknown and at autopsy the disorder is associated with three types of abnormal protein buildups in brain cells.

An example of a case in which bvFTLD was suspected is a recent court martial in which this writer was retained as an expert. It involved a twenty five year old male enlistee who began to exhibit sexually inappropriate behavior with underage girls in his extended family and their friends two years earlier. He denied any prior sexually inappropriate behavior and no witnesses came forward prior to or during the trial to testify that he had molested them. This is relevant because sexually predatory behavior is typically exhibited in the teens or earlier.

 A clinical examination for bvFTLD should include a structural MRI scan that may reveal frontal lobe and/or anterior temporal lobe bilateral or asymmetric atrophy, however, in the early stages a scan may appear normal which was the finding in this case. Even so, if bvFTLD is a rule out diagnosis a baseline MRI is important because it can be compared to imaging done at a later date and may reveal evidence of atrophy that might otherwise be interpreted as normal in later MRI’s viewed without benefit of comparison. In addition, a battery of neuropsychological tests may be considered but would probably not be definitive in making the diagnosis in the early stages without corroborating evidence from imaging studies. 

A diagnosis of bvFTLD would no doubt have been of value in mitigating the charges in this case and may yet be a factor in an appeal if evidence surfaces later to support the diagnosis. However, this man would probably choose his prison sentence rather than being diagnosed with bvFTLD because it is a progressive, untreatable fatal disease, in other words, a death sentence.

Further reading:

Drubach, D., Rabinstein, A. and Molano, J. Free Will, Freedom of Choice and Frontotemporal Lobar Degeneration. Mens Sana Monogr. 2011 Jan-Dec; 9(1): 238–250. (Available at www.pubmed.gov).

*Daubert Institute for Forensic Psychology. www.daubertinstitute.com


TASA Article Disclaimer

This article discusses issues of general interest and does not give any specific legal or business advice pertaining to any specific circumstances.  Before acting upon any of its information, you should obtain appropriate advice from a lawyer or other qualified professional.

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