The court so ruled in Commonwealth v. Delbridge, 2002 WL 32170269, Sept. 25, 2003. The defendant was charged with sexually molesting his daughter and son. They were six and four years old, respectively, at the time of the alleged crimes and the investigation. (Each turned a year older before trial.) Their mother, who had herself been molested as a child, had alleged sex abuse of the daughter when she was two years old. The children were repeatedly interviewed during this investigation by the state police, a psychologist, a social services worker, the prosecutor, and a pediatrician. None of the interviews was electronically recorded.

The defendant contended that his children's memories had been altered-- "tainted"-- by these events, so that neither their in-court testimony nor hearsay accounts of their interviews should be admitted at his trial. The trial court conducted a pre-trial hearing to determine whether the children were competent as witnesses, but it did not permit the defendant there to explore the interviews the children had undergone. The court found the children competent. It also found their interview statements admissible as hearsay. The defendant was convicted at trial. He appealed.

The Pennsylvania Supreme Court surveyed the states and found that several--Washington, New Jersey, Delaware, Michigan, and Wyoming-- had decided that "taint" of the memory of a child witness could be shown before trial, to exclude the child's testimony from trial. New York has conflicting trial court decisions on the issue. Alaska, Kentucky, and Ohio have rejected requests to make taint challenges before trial. (Georgia, New Hampshire, and Maine, the court found, permit evidence of taint to be presented at trial.)

The Pennsylvania court reasoned that a child with a tainted memory would not have an "independent memory of an actual event" and so would not be competent to testify. Hence, taint challenges should be heard during pre-trial competency hearings.

Expert testimony can be taken on taint, the supreme court said. Trial courts will need to decide, case by case, whether expert testimony would be helpful.