Factual background: On the evening of July 14, 1990, the victim was walking from a convenience store to her home when an assailant came from behind her, put one hand on her throat and one on her waist, and forced her to walk with him. The assailant stabbed her in the side as they walked, and the victim lost consciousness. When she awoke, the assailant was walking her to some bushes near an apartment complex. The assailant then repeatedly assaulted the victim sexually.

In a jury trial before the Chester County Court of Common Pleas, Dale Brison was convicted of rape, kidnapping, aggravated assault, carrying a prohibited offensive weapon, and three counts of involuntary deviate sexual intercourse. Brison was sentenced to 18 to 42 years of imprisonment. His term was 8 to 20 years for rape and 4 to 10 years for assault, to be served consecutively. He also received 6 to 12 years for each of the involuntary deviate sexual intercourse convictions (although each of these was to run concurrently, they were to be served consecutively with the other sentences). Brison sought DNA testing during the trial, but his request was denied.

Prosecutor's evidence at trial: The prosecution based its case on several points:

· There were two separate victim identifications of Brison near the victim's apartment building.

· A hair sample from the scene of the crime was consistent with Brison's.

· Brison's alibi, sleeping on the couch of his home, was corroborated only by his mother.

Postconviction challenges: In 1992 the Pennsylvania Superior Court ruled (618 A.2d 420) that DNA testing must be performed if the evidence had been maintained and the semen stain from the victim's underwear was not badly degraded. It also ruled that the burden of the cost of this test was upon the Commonwealth.

DNA results: Cellmark Diagnostics reported that no result was discernible from the vaginal swab, but the semen stain from the victim's panties yielded results that exculpated Brison as the assailant.