Delaware v. Fensterer

An FBI agent testified at Fensterer's (defendant) murder trial that a hair found at the crime scene had been forcibly removed, based on one of three possible characteristics, but he could not recall which specific characteristic he had actually relied upon; Fensterer's own expert testified the agent had told him it was a now-discredited characteristic. The Delaware Supreme Court reversed Fensterer's conviction, finding the agent's memory lapse deprived Fensterer of effective cross-examination, and Delaware sought Supreme Court review.