Commonwealth v. Davis - Superior Court - December 17, 2007http://www.aopc.org/OpPosting/Superior/out/a29031_07.pdf
The determination of a witness's competency rests within the sound discretion of the trial court. The decision of the trial court will not be disturbed absent a clear abuse of that discretion. The "standard of review of rulings on the competency of witnesses is very limited indeed. "
In Pennsylvania, the general rule is that every witness is presumed to be competent to be a witness. However, young children must be examined for competency pursuant to the following test:
(1) The witness must be capable of expressing intelligent answers to questions;
(2) The witness must have been capable of observing the event to be testified about and have the ability to remember it; and,
(3) An awareness of the duty to tell the truth.
If there is an allegation of taint, the inquiry centers on the second element. The “appropriate venue” for investigation into such a claim is a competency hearing , centered on the inquiry into the minimal capacity of the witness to communicate, to observe an event and accurately recall that observation, and to understand the necessity to speak the truth.
Pennsylvania courts have recognized that an immature witness’s testimony can be tainted by the inquiries of adults. In that instance, the core belief underlying the theory of taint is that a child's memory is peculiarly susceptible to suggestibility so that when called to testify a child may have difficulty distinguishing fact from fantasy. Taint is the implantation of false memories or the distortion of real memories caused by interview techniques of law enforcement, social service personnel, and other interested adults, that are so unduly suggestive and coercive as to infect the memory of the child, rendering that child incompetent to testify.
The capacity of young children to testify has always been a concern, since immaturity can impact a child's ability to meet the minimal legal requirements of competency. Common experience informs us that children are, by their very essence, fanciful creatures who have difficulty distinguishing fantasy from reality; who when asked a question want to give the “right” answer, the answer that pleases the interrogator; who are subject to repeat ideas placed in their heads by others; and who have limited capacity for accurate memory.
In order to trigger an investigation of competency on the issue of taint, the moving party must show some evidence of taint. Once some evidence of taint is presented, the competency hearing must be expanded to explore this specific question. During the hearing the party alleging taint bears the burden of production of evidence of taint and the burden of persuasion to show taint by clear and convincing evidence. Pennsylvania has always maintained that since competency is the presumption, the moving party must carry the burden of overcoming that presumption .