Appellant argues that CSAAS is not a recognized diagnosis within the field of psychology. The Court uses three criteria to assess the admissibility of scientific expert witness testimony. 1) The subject matter of the testimony must be beyond the understanding of laypersons and be distinctly related to some science. 2) The expert must possess sufficient skill, experience, or knowledge within the science to raise the inference that his testimony will assist the trier of fact. 3) The scientific basis of the expert testimony must be in such a state of development so as to permit the expert to make a reasonable opinion.
The purpose of CSAAS is to define a common language for clinical psychologists dealing with child sexual abuse, and is not intended as a means of detecting the existence of abuse. Because it is not diagnostic, the majority of courts have limited its admissibility. Some jurisdictions require a limiting instruction, others will not admit the testimony if offered to prove abuse occurred, while others will admit it solely to rehabilitate the victim’s credibility. A few jurisdictions never admit it because it has not obtained scientific acceptance.
CSAAS testimony is restricted because it offers no help to the jury of proof that abuse occurred. It is considered unreliable, there is considerable controversy and dispute over the inclusive traits, and it includes behaviors that may manifest in a child who was not sexually abused.
This Court believes that admissibility without restrictions would run too high a risk of misleading the jury and therefore be more prejudicial than probative. This Court will admit CSAAS testimony for the sole purpose of explaining a victim’s specific behavior which might be incorrectly construed as inconsistent with an abuse victim or to rebut an attack on the victim’s credibility.
This Court also determines that the expert’s testimony was proper in this case. He never stated that D-2 was abused because she represents a classic case of CSAAS. The majority of the testimony merely explained her behavior. The explanation of why she did not exhibit the 5th trait was unnecessary, but the Court cannot say it adversely affected the appellant’s substantial rights. CSAAS was not the sole basis for his ultimate conclusion that her case represented a classic pattern of a long history of sexual abuse. He performed a battery of psychological and intelligence tests, and based his opinion on the totality of his examination.