Science has its limitations

In his cross-examination of Dr. Joseph Wu, Prosecutor Ric Ridgway asked what kind of diagnosis a doctor could make from a PET scan alone. In a vacuum. With no corroborating evidence.

Not much, Wu admitted.

Ridgway then asked where Wu had received the outside information he used, along with Couey's raw scans, to make a determination. Wu said the information had come from Robert Berland and Richard Carpenter, both also witnesses for the defense. He had received Carpenter's information only this morning.

Ridgway asked Wu whether he had testified for the defense or prosecution before in death penalty trials. The defense, Wu said.

He ended his questioning by asking whether every person with Couey's brain scan abnormality would kidnap, rape and murder a young girl. The answer was no.

-- Elena Lesley