DENVER - Colorado's first prosecutor-led DNA exoneration of a man wrongfully convicted of murder came after a review of nearly 5,000 cases in a review effort that is spreading nationwide. During the two-year effort, Julie Selsberg, a senior assistant attorney general, and an investigator found one case that troubled them: That of 51-year-old Robert Dewey, a drifter convicted in 1996 and sentenced to life in prison for the 1994 rape and murder of 19-year-old Jacie Taylor in her apartment in the western Colorado city of Palisade. Dewey was freed on April 30 after DNA used to convict him was retested with Selsberg's help. The DNA, found on the victim, was traced to Douglas Thames Jr., who is serving a life sentence for the 1989 rape and strangling of businesswoman Susan Doll, 39, in Fort Collins. It was a victory for Dewey, who warned a judge and prosecutors at sentencing: "There's still a killer out there." It also was a win for the conviction integrity unit in Colorado, the Justice Review Project, funded by a $1.2 million federal grant. Dallas created the first such unit in 2007, followed by New York City; Cook County, Ill.; Santa Clara, Calif.; New Orleans and Suffolk County, Mass. "What's the cost of justice?" said Denver District Attorney Mitch Morrissey, who with Attorney General John Suthers created the unit. "We found this case, and it made a huge difference."