pat warrick focused on the ridge patterns and breaks in the patterns. these are unique to each person. there was no doubt the print on dawn fehring's bed sheet was made by eric hayden. eric hayden was arrested and charged with first-degree murder. prosecutors were convinced they had an ironclad case. but would the judge allow this evidence to be used in court? >>> as eric hayden awaited trial for the murder of dawn fehring, prosecutors had to deal with a number of problems. the technology used to reveal the print had never been admitted as evidence in a criminal trial. >> the standard argument in this particular type of case is that the evil empire, the cops are out there and they're just trying to convict innocent people out here of murder and all kinds of terrible crimes, and they'll stop at nothing to do that, including taking computer evidence, manipulating it, adding information, putting stuff in there that would unfairly bias the case against their client. >> when prosecutors walked into court, they had to convince the judge that the only thing th