With the help of new DNA evidence and Northwestern’s Center on Wrongful Convictions, two men were released from prison Friday after serving 27 years for the alleged rape and murder of a 9-year-old girl.

But the Cook County State’s Attorney’s Office is seeking a new trial against the men, Michael Evans, 44, and Paul Terry, 44, although DNA from the men showed no match with semen collected from the body of Lisa Cabassa, who was found dead on Chicago’s South Side in 1976. Both men were 17 when the crime occurred.

The new DNA evidence does not prove the men are innocent, according to a spokesman for the Cook County Prosecutor’s Office.

“We think the evidence is there that these gentlemen were responsible for the crime,” spokesman Tom Stanton said.

Exoneration based on DNA evidence is more difficult in a murder case because there is no victim account to limit the number of people involved, said Karen Daniel, a lawyer with NU’s center who is representing Evans and pushed for DNA testing.

During the original trial, the only eyewitness in the case admitted to the jury that she changed her police account several times, Daniel said.

“The conviction entirely rested on her testimony,” Daniel said. “In high-profile crimes that provoke emotional response, there can be a temptation to convict even with shaky evidence.”

Robert Warden, executive director for the center, said the prosecution’s only eyewitness is not reliable and there is not enough evidence for a retrial.

“There is not a shred of credible evidence and here they are threatening to take these poor kids back to trial,” Warden said. “They just don’t want to admit they are wrong.”

Assistant State’s Attorney Mark Ertler declined to elaborate on any new developments in the ongoing case.

“We are set for retrial,” Ertler said. “We have been conducting a very thorough investigation of the entire case.”